Category PLUMBER’S AND. PIPE FITTER’S. CALCULATIONS MANUAL

RESTAURANTS

Posted by admin on 18/ 11/ 15

Подпись: ✓ fast code fact If you are a residential plumber, be aware that code requirements for commercial work can be very different from what you are accustomed to working with. Be sure that you are using the proper section of the code for the type of work that you are doing. There are a lot of restaurants in society. This is a common type of building for plumbers to work with. Finding the number of water closets and lavatories required in a restaurant is no more difficult than the other examples that we’ve been working with. However, there are additional requirements for restaurants.

Essentially, you must check with your local code office and comply with minimum requirements that are established by the Board of Health.

Before we do a sizing example for a restaurant, let’s discuss two alternative options. You will notice if you look at the headings in Figure 9.4, that the number 6 and the number 17 are next to the heading for restaurants. We’ve already discussed the option of number 6; it is the one where one bathroom might be allowed for use by both sexes. The option pertaining to number 17 are that if alcoholic beverages will be served, the establishment must meet facility requirements as set forth for clubs or lounges.

Now, let’s do a sizing example. Assume that the restaurant we are working with is rated for 250 people. How many toilets are needed? Four water closets are required in each restroom. What is the required number of lavatories? The building calls for three lavatories in each restroom. Do you notice a difference in the ratings for restaurants, compared to the other types of buildings we have done thus far? If you review the tables, you will see that restaurants required, in almost all cases, the same number of fixtures for males as for females. In previous examples, female restrooms required more fixtures. This is not a big issue, just something i wanted to point out.

RETAIL STORES

Posted by admin on 18/ 11/ 15

The minimum fixture requirements for retail stores differ from the examples that we have just been working with. However, the concept and approach of computing the needs is same. Refer to Figure 9.3 for listings that pertain to retail stores. You can see that the table is very similar, in layout, to the one we have just been using. Pay particular attention to the number 6 at the heading of retail stores. Refer back to Figure 9.2 for an explanation of the note. You will find that one bathroom facility can be used by both males and females in certain types of occupancies. For example, an office with 1200 square feet, or less, can be served by a single restroom for both sexes. A retail store with 1500 square feet, or less, can also be served by one restroom, unless the store is classified as a service station. Other types of buildings that may qualify for a single bathroom are restaurants, self-service laundries, beauty salons, and barber shops. In all cases, the use of a single restroom is contingent on the square footage of the building. With this said, let’s run through a sample sizing example.

Assume that our sample building will accommodate 59 people. Use the table in Figure 9.3 to determine the minimum number of plumbing fixtures required. For the purposes of this exercise, assume that the single-bathroom rule is not applicable. Go ahead, run the numbers, and then compare them with mine.

You should have found that the male restroom requires two water closets. A total of three water closets is needed for the female restroom. The male restroom is required to have only one lavatory, but the female restroom is required to have three lavatories. Only one drinking fountain is needed, subject to building design. By this, I mean that a drinking fountain is required on each

200 sq ft
Retail stores6 per person	Persons (total)	Male	Female
	1-35	1	1
	36-55	1	2
	56-80	2	3
	81-100	2	4
	101-150 For each additional 200	2	5
	persons over 150, add	1	1.757

Drinking fountains

Persons (total)	Male	Female	Persons	Fixtures
1-15	1	1	1-100	1
16-35	1	2	101-250	2
36-60	1	3	251-500	3
61-125	2	4	501-1000	4
For each			Not less than one
additional 200			fixture each floor
persons over 125, add	1	1.757	subject to access.

FIGURE 9.3 ■ Minimum fixtures for retail stores. (Courtesy of Standard Plumbing Code)

floor of the building, subject to access. If you did not arrive at these numbers, go over the table again and see if you can find the error in your calculations.

COMMERCIAL BUILDINGS OF MULTIPLE TENANTS

Posted by admin on 18/ 11/ 15

Commercial buildings of multiple tenants is our first topic of conversation (Fig. 9.1). This type of building can include a number of uses. Look at the table in Figure 9.1. You can see headings for water closets, lavatories, drinking fountains, and bathing fixtures. At first glance, the table seems simple enough, and it is not too difficult. But it can be confusing, so let’s go through some sizing examples.

I want you to assume that there will be 62 people rated for the building that we are sizing. How many fixtures of each type will the building require? Take a moment to work the numbers, and then read the following results to see if you arrive at the same number that I do.

if you look under the heading for water closets, you will see that you need three for men and four for women. Also note the number 3 next to the water closet heading. Refer to Figure 9.2 for an explanation of the number. if you look at the number 3 in Figure 9.2, you will see conditions for various types of buildings within the general group that we are working with. For example, the statement requires urinals in male restrooms of restaurants, clubs, lounges, and so forth.

How many lavatories are needed in the restroom for women? The correct answer is three. Two lavatories are needed in male restrooms. How many bathing units are required? None, but our building will need a drinking fountain. Also note that drinking fountains are required on each floor, so this might increase the number of fixtures needed, depending upon building design. Pay attention to all details and footnotes when you use code charts and tables for sizing.

You probably already have a handle on this type of building, but let’s do one more quick exercise. Using the same type of building, change the occupancy number to 125 people. What are the fixture requirements? We need four toilets in the male restroom and five in the female restroom. Two lavatories are required in the male restroom, and three are needed for the ladies. Drinking fountains are needed in the building. A minimum of two fountains is required.

								Bathtubs, showers
Building or occupancy2	Occupant content2	Water closets3		Lavatories4		and miscellaneous fixtures
Common toilet	Use the sq ft per	Persons (total)	Male	Female	Persons (total)	Male	Female	Drinking fountains
facilities for areas of	person ratio	1-50	2	2	1-15	1	1	Persons Fixtures
commercial buildings of multiple tenants9-9	applicable to the single type occupancy(s) occupying the greatest aggregate floor area (Consider separately each floor area of a divided floor)	51-100 101-150	3 4	4 5	16-35 36-60	1 2	2 2	1-100 1 101-250 2
	For each	1	1.57	61-125	2	3	251-500 3
	additional 100			For each	1	1.57	501-1000 4
	persons over 150, add			additional 120 persons over 125, add			Not less than one fixture each floor subject to access.

FIGURE 9.1 ■ Minimum fixtures for commercial multi-tenant buildings. (Courtesy of Standard Plumbing Code)

Notes:

1. The figures shown are based upon one fixture being the minimum required for the number of persons indicated or any fraction thereof.

2. The occupant content and the number of required facilities for occupancies other than listed shall be determined by the plumbing official. Plumbing facilities in the occupancies or tenancies of similar use may be determined by the plumbing official from this table.

3. Urinals shall be required in male restrooms of elementary or secondary schools, restaurants, clubs, lounges, waiting room of transportation terminals, auditoriums, theaters, and churches at a rate equal to Vi of the required water closets in Table 407. Required urinals can be substituted for up to Уз of the required water closets. The installation of urinals shall be optional in the female restrooms of previously stated occupancies and shall be optional in both male and female restrooms of all other occupancies. Optional urinals may be substituted for up to Уг of the required water closets in the male and female restrooms.

4. Twenty-four linear inches (610 mm) of wash sink or 18 inches (457 mm) of a circular basin, when provided with water outlets for such space, shall be considered equivalent to 1 lavatory.

5. When central washing facilities are provided in lieu of washing machine connections in each living unit, central facilities shall be located for the building served at the ratio of not less than one washing machine for each 12 living units, but in no case less than two machines for each building of 15 living units or less. See 409.4.5.

6. A single facility consisting of one water closet and one lavatory may be used by both males and females in the following occupancies subject to the building area limitations:

Maximum building

Occupancy area (sq ft)

Office

Retail Store (excluding service stations) Restaurant

Laundries (Self-Service)

Beauty and Barber Shops

1200

1500

500

1400

900

7. After totaling fixtures, round up any fraction to the next highest whole number of fixtures.

8. Common toilet facilities (separate for males and females) for each floor are acceptable in lieu of separate facilities required by this section only when the applicable building occupant has common access from within the building. When tenancies, rental units, etc., are to be provided with separate facilities of a partial nature, such facilities are not deductible from the total common facilities required.

9. (a) Applicable to small stand-up restaurants and similar occupancies.

(b) Not applicable to do-it-yourself laundries, beauty shops and similar occupancies where persons must remain to receive personal services.

10. (a) Light manufacturing is applicable to those manufacturers manufacturing finished products which require no special equipment to handle single finished products may require special equipment to handle the products when packaged in containers containing multiple products.

(b) Heavy manufacturing is applicable to those manufacturing processes requiring overhead cranes or similar equipment for the movement of raw materials and/or the finished products.

Подпись: 11. (a) Light Storage: Light storage is the storage of items which can be handled without the aid of special handling equipment such as cranes, forklifts or similar equipment. (b) Heavy Storage: Heavy storage is the storage of items which require special equipment for handling such as cranes, forklifts or similar equipment. 12. For other than industrial areas of the occupancy, see other applicable type oc-cupancies (applicable to facilities provided due to inaccessibility of those in main or initial occupancy). 13. As required by the American Standard Safety Code for Industrial Sanitation in Manufacturing Establishments (ANSI Z4.1). 14. Where there is exposure to skin contamination with poisonous, infectious, or irritating materials, provide 1 lavatory for each 15 persons. 15. Laundry trays, 1 for each 50 persons. Slop sinks, 1 for each 100 persons. 16. For exclusively male or female dorms, the fixtures shall be double the amount required for the particular gender in a co-ed dorm. 17. If alcoholic beverages are to be served, facilities shall be as required for clubs or lounges.

FIGURE 9.2 ■ (Continued)

CALCULATING MINIMUM PLUMBING FACILITIES

Posted by admin on 18/ 11/ 15

Подпись: alculating minimum plumbing facilities is a common part of a master plumber’s job. Knowing and understanding what is required in a building is not only a requirement for plumbers. Architects and engineers are often the people who determine the requirements for a new building. Local plumbing codes dictate minimum plumbing facilities. All plumbers have to do is understand the information provided for them in their codebooks. The information given by the codes is fairly simple, but gaining a complete understanding of it can be a bit intimidating. If the process is approached too lightly, misconceptions can cause mistakes. The people responsible for determining what plumbing will be included in a building cannot afford to make mistakes.

CALCULATING MINIMUM PLUMBING FACILITIES Подпись: ► sensible shortcut It is common for plumbers to be provided with detailed blueprints when bidding jobs. The drawings will normally be submitted to a code enforcement office for approval. During this process, there are many ways for mistakes to be caught.

Подпись: If the person drawing the plans makes an error, the code officer who is working with the drawings is likely to find the problem. Plumbers bidding the job might catch the discrepancy.

Some jobs are not engineered. There are times when plumbers are expected to calculate the minimum plumbing needs for a building. Plus, plumbers who wish to

165

gain a master’s license will have to pass an examination that is likely to require them to compute plumbing requirements. With this in mind, let’s look at some tables that might be used to figure the requirements for plumbing fixtures in various types of buildings.

WELL-X-TROL QUICK SIZING FORM

Posted by admin on 17/ 11/ 15

(We suggest you make an office copy of this page when ready to calculate.)

For selecting WELL-X-TROLs for a different running time than ESP I or ESP II, and/or at pressure ranges the same or different than 20/40,30/50, 40/60:

THINGS YOU MUST KNOW

1, System flow rate (pump capacity or discharge) GPM

. Min.

. Psig. Psig

. ESPVol.

2. Desired running time, in minutes and fractions of minutes (1.5 min. = 1 min. 30 sec )

3. Pump cut-in. in gauge pressure

4. Rump cut-out, in gauge pressure

CALCULATING TANK SIZE

5. Multiply Line 1 by Line2 and enter ESP Volume

WELL-X-TROL QUICK SIZING FORM

, P. F.

, Gals.

Refer to Table 2 and select WELL-X-TROL model that is greater than Line 7 tor “Total Volume” and Line 5 is less than “Maximum ESP Volume"

WELL-X-TROL QUICK SIZING FORM

THINGS YOU MUST KNOW

1. System flow rate (pump delivery)

12.5 GPM

1.5 Min. 25 Psig 45 Psig

2. Desired running time, in minutes and

fractions of minutes(1.5 min. = tmin.30sec.)

3. Pump cut-in. in gauge pressure

WELL-X-TROL QUICK SIZING FORM

18.8 ESPVol. 34 P. F.

7. Divide Ltne 5 by Line 6 and enter minimum total WELL-X-TROL volume

55.2 Gals

WELL-X-TROL QUICK SIZING FORM

WX-251

FIGURE 8.35 ■ Pressure tank sizing form. (Courtesy of McGraw-Hill)

WELL-X-TROL QUICK SIZING FORM

FIGURE 8.36 ■ Tank tee being used with a stand – type pressure tank. (Courtesy of McGraw-Hill)

WELL-X-TROL

Union

If /’^–Shut-off Г ’’ valve

To system

psig

Pressure switch

WELL-X-TROL QUICK SIZING FORM

FIGURE 8.37 ■ Diagram of multiple pressure tanks being installed together. (Courtesy of McGraw-Hill)

REMAINING TABLES

Posted by admin on 17/ 11/ 15

The remaining tables are different in content, but the procedures for using them are the same. Once you know the number of bedrooms and bathrooms for a dwelling, you can quickly and easily determine the minimum requirements for a water heater. You have just seen how simple the tables are. When you have a water heater to size, just refer to the tables in this chapter (Fig. 7.4, to 7.10) or the tables in your local codebook.

Number of bedrooms	2	3	4	5
Storage capacity (gallons)	30	40	40	50
Input in Btuh	36,000	36,000	38,000	47,000
Draw (gallons per hour)	60	70	72	90
Recovery (gallons per hour)	30	30	32	59

FIGURE 7.4 ■ Water heating sizing table for gas heaters (minimum recommendations). Assume 2 to 21/2 bathrooms.

Number of bedrooms	2	3	4	5
Storage capacity (gallons)	40	50	50	66
Input in Btuh	4.5 KW	5.5 KW	5.5 KW	5.5 KW
Draw (gallons per hour)	58	70	72	88
Recovery (gallons per hour)	18	22	22	22

FIGURE 7.5 ■ Water heating sizing table for electric heaters (minimum recommendations). Assume 2 to 21/2 bathrooms.

Number of bedrooms	2	3	4	5
Storage capacity (gallons)	30	30	30	30
Input in Btuh	70,000	70,000	70,000	70,000
Draw (gallons per hour)	89	89	89	89
Recovery (gallons per hour)	59	59	59	59

FIGURE 7.6 ■ Water heating sizing table for oil-fired heaters (minimum recommendations). Assume 2 to 21/2 bathrooms.

Number of bedrooms	3	4	5	6
Storage capacity (gallons)	40	50	50	50
Input in Btuh	38,000	38,000	47,000	50,000
Draw (gallons per hour)	72	82	90	92
Recovery (gallons per hour)	32	32	40	42

FIGURE 7.7 ■ Water heating sizing table for gas heaters (minimum recommendations). Assume 3 to 31/2 bathrooms.

Number of bedrooms	3	4	5	6
Storage capacity (gallons)	50	66	66	80
Input in Btuh	5.5 KW	5.5 KW	5.5 KW	5.5 KW
Draw (gallons per hour)	72	88	88	102
Recovery (gallons per hour)	22	22	22	22

FIGURE 7.8 ■ Water heating sizing table for electric heaters (minimum recommendations). Assume 3 to 3V2 bathrooms.

Number of bedrooms	3	4	5	6
Storage capacity (gallons)	59	59	59	59
Input in Btuh	70,000	70,000	70,000	70,000
Draw (gallons per hour)	89	89	89	99
Recovery (gallons per hour)	59	59	59	59

FIGURE 7.9 ■ Water heating sizing table for oil-fired heaters (minimum recommendations). Assume 3 to 3V2 bathrooms.

Column 1	Column 2
Buildings of ordinary tightness	Buildings of unusually tight construction
Condition	Size of opening or duct	Condition	Size of opening or duct
Appliance in unconfined2 space	May rely on infiltration alone.	Appliance in unconfined2 space: Obtain combustion air from outdoors or from space freely communicating with outdoors.	Provide two openings, each having 1 sq. in. per 5,000 Btu/h input.
Appliance in confined4 space 1. All air from inside building	Provide two openings into enclosure each having one square inch per 1,000 Btu/h input freely communicating with other unconfined interior spaces. Minimum 100 sq. in. each opening.	Appliance in confined4 space: Obtain combustion air from outdoors or from space freely communicating with outdoors.	1. Provide two vertical ducts or plenums: 1 sq. in. per 4,000 Btu/h input each duct or plenum. 2. Provide two horizontal ducts or plenums: 1 sq. in. per 2,000 Btu/h input each duct or plenum. 3. Provide two openings in an exterior wall of the enclosure: each opening 1 sq. in per 4,000 Btu/h input. 4. Provide one ceiling opening to ventilated attic and one vertical duct to attic: each opening 1 sq. in. per 4,000 Btu/h input.
2. Part of air from inside building	Provide two openings into enclosure3 from other freely communicating unconfined2 interior spaces, each having an area of 100 sq. in. plus one duct or plenum opening to outdoors having an area of 1 sq. in. per 5,000 Btu/h input rating.
3. All air from outdoors: Obtain from outdoors or from space freely communicating with outdoors.	Use of any of the methods listed for confined space in unusually tight construction as indicated in Column 2.		5. Provide one opening in enclosure ceiling to ventilated attic and one opening in enclosure floor to ventilated crawl space: each opening 1 sq. in. per 4,000 Btu/h input.

’For location of opening, see Section 1307(c).

2As defined in Section 122,

3When the total input rating of appliances in enclosure exceeds 100,000 Btu/h, the area of each opening into the enclosure shall be increased 1 sq. in. for each 1,000 Btu/h over 100,000,

4As defined in Section 104(h).

FIGURE 7.10 ■ Size of combustion air openings or ducts for gas-or liquid-burning water heaters. [Courtesy of Uniform Plumbing Code)

ome plumbers work their entire careers without ever having to know anything about water pumps. Other plumbers deal with pumps on a frequent basis. The difference is where the plumbers work. I’ve never worked in New York City, but I suppose there are not many water pumps to be installed or serviced. But where I live, in Maine, there are more homes served by private water wells than you can shake a stick at. When I lived in Virginia, there were plenty of water pumps, too. Some of the pumps are jet pumps and others are submersible pumps. The two are very different, even though they do the same job.

Jet pumps are at their best when used in conjunction with shallow wells, with depths of say 25 feet or less. Two-pipe jet pumps can be used with deep wells, but a submersible pump is usually a better option for deep wells. Sizing water pumps and pressure tanks is routine for some plumbers and foreign to others. This chapter is going to give you plenty of data to use when working with pump systems.

The illustrations I have to offer you in this chapter are detailed and selfexplanatory. I believe that you will be able to use this chapter as a quick-reference guide to most of your pump questions. Look over the following illustrations and you will find data on jet pumps, submersible pumps, and pressure tanks. The data will prove very helpful if you become involved with the installation, sizing, or repair of water pumps (Figs. 8.1 to 8.37).

135

This check list is intended to bdp in making reliable submersible pump installations. Other data for specific pumps may be needed.

1. Motor Inspection

___ Л. Verify thai lire model. HP or KW. voltage, phase

and heitz on the motor nameplate match the installation requirements. Consider any special comision resistance required.

___ B, Check that I he motor lead assembly ts tight in Uie

motor and that the motor and lead are not damaged.

___ C. Test insulation resistance using a 500 or l(MX) volt

DC inegohmmeier, from each lead wire to the motor frame, Resistance should be at least 20 megohms, motor only, no cable.

D. Keep a record of motor model number, HP or KW, voltage, date code and serial number,

2. Pump Inspection

___ A. Check that the pump rating matches the motor, and

that it is not damaged.

___ B. Verily that the pump shaft turns freely.

3. Pump/Motor Assembly

___ A. If not yet assembled, check that pump and motor

mounting faces are free from dirt and uneven paint

thickness.

___ B, Assemble the pump and motor together so their

mourning faces are in contact, then tighten assembly holis or nuts evenly to manufacturer specifications.

И it is visible, chuck dial the pump shaft is raised slightly by assembly to the motor, conlilining impeller running clearance.

___ C. If accessible, check that the pump shaft rums freely.

___ D. Assemble the pump lead guard over the motor

leads. Do not eui nr pinch lead wire during assembly or handling of the pump during installation.

4. Power Supply and Controls

__ A. Verify that the power supply voltage, here?., and

KVA capacity malch motor requirements.

B, Use a matching control box with each single phase three wire motor.

___ C. Check that the electrical installation arid controls

meet all safety regulations and match the motor requirements, including fuse or circuit breaker size and motor overload protection. Connect all metal plumbing and electrical enclosures to (he power supply ground in prevent shock hazard, Comply with National and local codes.

5. Lightning and Surge Protection

___ A. Use properly rated surge (lightning) arresiors on all

submersible pump installations unless the installation is operated directly from an individual generator and/or is not exposed to surges. Motors 5HP and smaller which are marked “Equipped with Lightning Arrestors’contain internal arrestors.

B. Ciround all above ground arrestors with copper wire directly to the motor frame. or to metal drop pipe or casing which reaches below the well pumping level, Connecting to a ground rod does not provide good surge protection.

6. Electrical Cable

___ A. Use cable suitable for use in water, sized to carry’ the

motor current without overheating in water and in air, and complying with local regulations. To maintain adequate voltage at die motor, use lengths no longer than specified in die motor manufacturer s cable charts,

___ B. Include a ground wire to liie pump if required by

codes or. surge protection, connected lo the power supply ground Always ground any pump operated outside a drilled well.

7. Well Conditions

___ A, For adequate cooling, motors must have at least the

water flow shown on ils nameplate. If well conditions and construction do not assure this much water How will always come from below the motor, use a flow’ sleeve as shown in the Application, Installation & Maintenance Manual

___ B. If water temperature exceeds JO degrees C <86 T).

reduce live motor loading or increase the How rate to prevent overheating, as specified in the Application. Installation & Maintenance Manual.

B. Pump/Motor Installation

___ A. Splice motor leads lo supply cable using electrical

grade solder or compression connectors, and carefully insulate each splice with watertight tape or adhesive-lined shrink tubing, as shown in motor or pump installation data.

___ B. Support the cable to the delivery pipe every 10 feel

(3 meters) with straps or tape strong enough to prevent sagging. Use pads between cable and any metal straps.

___ C. A check valve in the delivery pipe is recommended,

even though a pump may be reliable without one. More than one check valve may be required, depending cm valve rating and pump setting. Install the lowest check valve below the lowest pumping level of the well, lo avoid hydraulic shocks which may damage pipes, valve or motor.

___ D. Assemble all pipe joints as lightly as practical, to

prevent unscrewing from motor torque. Recommended torque is at least 10 pound feet per HP (2 mcter-KG per KWi.

___ E. Set the pump fur enough below the lowest pumping

level to аччигс the pump inlet will always have at least the Net Positive Suction 1 lead |NPSI l) specified by the pump manufacturer, but at least 11) leet (3 meters) from the bottom of the well lo allow for sediment build up.

___ F. Cheek, insulation resistance from dry motor cable

ends to ground as the pump is installed, using а 5Ш or KM) volt DC megohm meter. Resistance may drop gradually as mere cable enters the water, but any sudden drop indicates possible cable, splice or motor lead damage. Resistance should meet motor manufacturer data,

9. After Installation

___ A. Check all electrical and waterline connections and

parts before starting the pump, Make sure water delivery will not wd any electrical parts, and recheck that overload protection in three phase controls meets requirements.

___ B. Strut the pump and check motor amps and pump

delivery. If normal, continue to run the pump until delivery is clear. If three phase pump delivery is low, it may be running backward because phase, sequence is reversed. Rotation may be reversed (with power off) by interchanging any two motor lead connections to the power supply.

___ C. Connect three phase motors for current balance

within 5% of average, using motor manufacturer instructions. Unbalance over 5c7c will cause higher motor temperatures and may cause overload trip, vibration, and reduced life.

___ D. Make sure that starling, running and stopping cause

no significant vibration or hydraulic shocks.

___ E. A Iter at least 15 minutes running, verify that pump

output, electrical input, pumping level, and other characteristics arc stable and as specified.

Date____________________ Filled In By

10. Installation Data

Well Identification_________________________________ _________________________________________

Check By ____________________________________ _

Date___ /____ (_____

Notes __________________________________________

KM A No.

Pump Inlet Setting___

Flow Sleeve: No

_ Yes. Dia.

Casing Depth______ Jt

□ Well Screen □ Perforated Casing From__ to_________ ft. &__ to________ ft-

– Well Depth_

Form No. 2207 2AM

REMAINING TABLES

Average water requirements for general
service around the home and farm
Each person per day, for all purposes		75 gal.
Each horse, dry cow, or beef animal		12 gal.
Each milking cow		35 gal.
Each hog per day		4 gal.
Each sheep per day		2 gal.
Each 100 chickens per day		4 gal.
Average amount of water required by
various home and yard fixtures
Drinking fountain, continuously flowing	50 to 100 gal. per day
Each shower bath	Up to 30 gal. @ 3-5 gpm
To fill bathtub		30 gal.
To flush toilet		6 gal.
To fill lavatory		2 gal.
To sprinkle V4" of water on each 1000
square feet of lawn		1б0 gal.
Dishwashing machine — per load	7 gal. @ 4 gpm
Automatic washer —per load	Up to 50 gal. @ 4-6 gpm
Regeneration of domestic water softener		50-100 gal.
Average flow rate requirements by
various fixtures
(gpm = gal. per minute; gph =	gal. per hour)
Shower		3-5 gpm
Bathtub		3-5 gpm
Toilet		3 gpm
Lavatory		3 gpm
Kitchen sink		2-3 gpm
У2” hose and nozzle		200 gph
1/4" hose and nozzle		300 gph
Lawn sprinkler		120 gph

FIGURE 8.3 ■ Average water requirements for general service. (Courtesy of McGraw-Hill)

Each horse	Approx. Gallons Per Day 12
Each producing cow	15
Each nonproducing cow	12
Each producing cow with drinking cups	30-40
Each nonproducing cow with drinking cups	20
Each hog	4
Each sheep	2
Each 100 chickens	4-10
Yard fixtures:
Vi-inch hose with nozzle	200
M-inch hose with nozzle	300
Bath houses	10
Camp
Construction, semipermanent	50
Day (with no meals served)	15
Luxury	100-150
Resorts (day and night, with limited plumbing)	50
Tourists with central bath and toilet facilities	35
Cottages with seasonal occupancy	50
Courts, tourists with individual bath units	50
Clubs
Country (per resident member)	100
Country (per nonresident member present)	25

FIGURE 8.4 ■ Daily water requirements. (Courtesy of McGraw-Hill)

Dwellings

Luxury

Multiple family, apartments (per resident)

Rooming houses (per resident)

Single family Estates _

Factories (gallons/person/shift)

Institutions other than hospitals Hospitals (per bed)

Laundries, self-serviced (gallons per washing, i. e., per customer)

Motels

With bath and toilet (per bed space)

Parks

Overnight with flush toilets Trailers with individual bath units Picnic

With bath houses, showers, and flush toilets With only toilet facilities (gal./picnicker) Restaurants with toilet facilities (per patron)

Without toilet facilities (per patron)

With bars and cocktail lounge (additional quantity) Schools Boarding

Day with cafeteria, gymnasiums and showers Day with cafeteria but no gymnasiums or showers Service stations (per vehicle)

Stores (per toilet room)

Swimming pools Theaters

Drive-in (per car space)

Movie (per auditorium seat)

Workers

Construction (semipermanent)

Day (school or offices per shift)

100-150

15-35

75-125

250-400

100

50-70

400

Providing an adequate water supply provides for a healthy family and higher production from livestock. Assuming the total daily requirement is calculated to be 1200 gpd (gallons per day), a pump would be selected for a capacity of 10 gpm (gallons per minute) based on the following formula:

1200 gph t 2 equals 600 gph (gal. per hr.)

FIGURE 8.4 ■ (Continued) Daily water requirements. (Courtesy of McGraw-Hill)

REMAINING TABLES

Engineering Data
Drop Cable Selection Chart

Single-phase, two or three-wire cable, 60 Hz (service entrance to motor)

REMAINING TABLES

Engineering data

Formulas and conversion factors
Centrifugal pumps

Volume

1 U. S, gallon – 231 cu. in,

1 U. S. gallon =■ 3-785 liters 1 Imperial gallon *1.2 U. S.

gallons

1 barrel (oil) я 42 U. S, gallons 1 cubic foot * 7.48 U. S, gallons

1 acre foot = 325,850 U. S.

gallons

1 cubic meter * 264,2 U. S.

gallons

Weight

1 U. S. gallon water weighs 8,35 lbs.

1 cubic foot water weighs

Head

1 lb. per sq. in. = 2.31 ft. of water 1 foot of water = 0-433 lbs. per sq. in. 1 inch of mercury = 1,133 ft. of water 1 atmosphere (sea level) – 14.7 lbs, per sq. in.

1 kilogram per sq. centimeter * 14,22 lbs. per sq. in.

Length

1 meter » 3.28 feet – 39.37 inches Power

1 horsepower = 745-7 watts 1 kilowatt * 1000 watts 1 kilowatt = 1.341 HP 100 boiler HP requires 7 gpm feed water approximately.

FIGURE 8.6 ■ Formulas and conversion factors for centrifugal pumps. (Courtesy of McGraw-Hill)

REMAINING TABLES

system

xtsll~x~trol

system

Relief valve

Submersible pump

REMAINING TABLES

FIGURE 8.7 ■ Pressure tank in use with a submersible pump. (Courtesy of McGraw-Hill)

REMAINING TABLES

О 1 2 3 456789 10 11 12

U. S. gallons per minute

FIGURE 8.8 ■ Performance rating chart for pump with 5 gallon-per- minute output. (Courtesy of McGraw-Hill)

REMAINING TABLES

FIGURE 8.9 ■ Performance rating chart for pump with 10 gallon-per- minute output. (Courtesy of McGraw-Hill)

1000

800

700

400

200

100

U. S. gallons per minute

FIGURE 8.10 ■ Performance rating chart for pump with 13 gallon-per – minute output. (Courtesy of McGraw-Hill)

REMAINING TABLES

800

700

400

200

100

U. S. gallons per minute

REMAINING TABLES

FIGURE 8.12 ■ Performance rating chart for pump with 25 gallon-per – minute output. (Courtesy of McGraw-Hill)

Output In gallons per hour

Discharge pressure 0 P. S.I.

			Impeller	Pres, switch	Suction	Discharge	Shipping
Model no.	HP	Volts	material	setting	pipe size	size	weight
8130	Уз	115	Plastic	20-40	1У4”	■1/4"	46 lbs.
8131	Уз	115	Brass	20-40	1У4"		48 lbs.
8150	y2	115/230	Plastic	20-40	1У4”	‘■’A"	48 lbs.
8151	y2	115/230	Brass	20-40	1У4"		50 lbs.
8170	3/4	115/230	Plastic	30-50	IV*’	%"	50 lbs.
8171	3/4	115/230	Brass	30-50	1У4"	%"	52 lbs.
8110	1	115/230	Plastic	30-50	1У4”		52 lbs.
8111	1	115/230	Brass	30-50	1У4"		53 lbs.

FIGURE 8.14 ■ Performance ratings for jet pumps. (Courtesy of McGraw-Hill)

Подпись: Impeller Pres, switch Suction Twin type Shipping Model Model HP Volts material setting pipe size drop pipe weight 1550 1050 Vz 115/230 Brass 30-50 1%" 1" x l'A” 65 lbs. 1575 1075 3/4 115/230 Brass 30-50 1У4" 1" X ІУ4" 71 lbs. 1575SW 1075SW % 115/230 Brass 30-50 1У." Г x 1УТ 66 lbs. 1510 1010 1 115/230 Brass 30-50 1У4" Г x l'A" 74 lbs. 1510SW 1010SW 1 115/230 Brass 30-50 1У4" 1" x I'A” 67 lbs. 1515SW 1015SW l‘/2 115/230 Brass 30-50 1У4” Г X l'A" 72 lbs.

FIGURE 8.15 ■ Performance ratings for multi-stage pumps. [Courtesy of McGraw-Hill)

REMAINING TABLES

FIGURE 8.16 ■ Shallow-well performance chart. (Courtesy of McGraw-Hill)

REMAINING TABLES

FIGURE 8.17 ■ A typical jet-pump set-up. (Courtesy of McGraw-Hill)

system

Pump

Dram

REMAINING TABLES

FIGURE 8.18 ■ A jet pump mounted on a pressure tank with a pump bracket. (Courtesy of McGraw-Hill)

REMAINING TABLES

FIGURE 8.19 ■ A typical piping arrangement for a jet pump. (Courtesy of McGraw-Hill)

REMAINING TABLES

FIGURE 8.20 ■ Bracket-mounted jet pump on a horizontal pressure tank. (Courtesy of McGraw-Hill)

REMAINING TABLES

FIGURE 8.21 ■ Small, vertical pressure tank installed above pump. (Courtesy of McGraw-Hill)

REMAINING TABLES

FIGURE 8.22 ■ Small, vertical pressure tank installed above pump. (Courtesy of McGraw-Hill)

REMAINING TABLES FIGURE 8.24 ■ An underground installation of a pressure tank. (Courtesy of McGraw-Hill)

REMAINING TABLES

FIGURE 8.25 ■ In-line pressure tank. (Courtesy of McGraw-Hill)

Stand models

FIGURE 8.26 ■ Stand-type pressure tank. (Courtesy of McGraw-Hill)

REMAINING TABLES

Model	Dimensions	Total	1,5/3,0 bar	2,0/3,5 bar	2,5/4,0 bar	System	Precharge	Shipping
No.	Diameter	Height	Volume		Drawdown		Connection	Pressure	Wt./Vol.
	mm	mm	Ltr	Liter	Liter	Liter	FT	bar	KG/m3
WX 2,6	156	228	2.6	1,0	0,9	0,8	3/4	1,5	1,0/,005
WX4	156	302	4,1	1,5	1,4	1,2	3/4	1.5	1,5/,007
WX8	200	320	8	3,0	2.6	2,4	3/4	1,5	2,3/,02
WX 18	280	380	18	6,7	6,0	5,4	3/4	1,5.	4,1 / ,03
WX33	280	630	33	12,4	10,9	9,9	3/4	1,5	6,8 / ,05

REMAINING TABLES

FIGURE 8.27 ■ Specifications for in-line pressure tanks. (Courtesy of McGraw-Hill)

10 bar series

Mode

WL 1855

560

805

801

560

805

180

560

1240

560

1700

300

750

1880

600

750

2340

800

1000

1960

1000

000

2740

600

2493

1200

2000

16 bar series

560

805

560

1240

560

1700

300

750

1880

600

750

2340

800

1801-20001

1960

1000

2740

1600

2000

2493

REMAINING TABLES

1,5/3,0 bar	2,0/3,5 bar	2,5/4,0 bar	System Connection	Precharge Pressure	Shipping Wt./Vol.
Liter	Drawdown Liter	Liter
FT	bar	KG /m3
30	27	24	2	3,5	59 / ,25
68	60	54	2	3,5	83 / ,39
113	99	90	2	3,5	155/,53
225	198	180	2	3,5	285/1,06
300	264	240	2	3,5	360/1,32
375	330	300	3	3,5	400 /1,96
600	528	480	3	3,5	540/2,74
750	660	600	3	3,5	780 / 3,59

30	27	24	2	3,5	59/,25
68	60	54	2	3,5	83 / ,39
113	99	90	2	3.5	155/,53
225	198	180	2	3,5	285 /1,06
300	264	240	2	3,5	360 /1,32
375	330	300	3	3,5	400 /1,96
600	528	480	3	3.5	540/2,74
750	660	600	3	3,5	7890/3,59

30	27	24	2	3,5	64 / ,25
68	60	54	2	3,5	102/,39
113	99	90	2	3,5	220 / ,53
225	198	180	2	3,5	400/1,06
300	264	240	2	3,5	505/1,32
375	330	300	3	3,5	560 / 1,96
600	528	480	3	3,5	756/2,74
750	660	600	3	3,5	1330/3,5

FIGURE 8.28 ■ (Continued) Specifications for pressure tanks with replaceable bladder designs. (Courtesy of McGraw-Hill)

REMAINING TABLES

FIGURE 8.29 ■ Detail for a tank-tee set-up. (Courtesy of McGraw-Hill)

	Dimensions	Total	Max.	Drawdown		ShipplRQ
Model	Diameter	Height	Volume	Accept.	2W40	30/50	40/50	m (Vo i. >
No.	(ini)	(in)	(tali)	Factor	(gala)	(gall)	(gala)	H>i feu 44>
WX-103-PS	12 V2	11 VA	8.6	028	3 1	2.7	22	20(2.4}
WX 200-PS	17 W	15 *8	140	0.31	5.2	43	38	29(4 0)

Precharge Pressure is 30 PSIG and Sys. Conn, is *4“ NPTM Filling lor 103-PS and i" NPTF Coupling lor 2Q0-PS. Maximum Working Pressure is 100 PSIG and Maximum Working Temperalure is 200" F.

FIGURE 8.30 ■ Pump-stand type of pressure tank. (Courtesy of McGraw – Hill)

REMAINING TABLES

FIGURE 8.31 ■ Underground pressure tank specifications. (Courtesy of McGraw-Hill)

REMAINING TABLES

When the pump starts, water enters the WELL-X-TROL as system pressure passes the minimum pressure precharge. Only usable water is stored.

WELL-X-TROL has a sealed-in air chamber that is pre-pfessurized before it leaves our factory. Air and water do not mix eliminating any chance of “waterlogging” through loss of air to system

When water is demanded, pressure in the air chamber forces water into the system. Since WELL-X-TROL does not waterlog and consistently delivers the maximum usable water, minimum pump starts are assured.

FIGURE 8.32 ■ How diaphragm pressure tanks work. (Courtesy of McGraw-Hill)

Maximum starts per 24 hr. day

Motor rating	Single phase	Three phase
Up to 3A hp	300	300
1 hp thru 5 hp	100	300
7 У2 hp thru 30 hp	50	100
40 hp and over		100

FIGURE 8.33 ■ Recommended maximum number of times a pump should start in a 24-hour period. (Courtesy of McGraw-Hill)

REMAINING TABLES

O’*

Operating pressure—psig

discharge 20/40 30/50 40/60

rate gpm (approx.) 2.5	ESP I	ESP II	ESP I	ESP II	ESP I	ESP II
WX-104	WX-201	WX-104	WX-202	WX-104	WX-202
5	WX-201	WX-205	WX-202	WX-205	WX-202	WX-250
7	WX-202	WX-250	WX-203	WX-251	WX-205	WX-251
10	WX-203	WX-251	WX-205	WX-302	WX-250	WX-302
12	WX-205	WX-302	WX-250	WX-302	WX-251	WX-350
15	WX-250	WX-302	WX-251	WX-350	WX-251	WX-350
20	WX-251	WX-350	WX-302	(2JWX-251	WX-302	(2)WX-302
25	WX-302	(2JWX-302	WX-302	(2)WX-302	WX-350	(3)WX-251
30	WX-302	(2)WX-302	WX-350	(DWX-302	WX-350	(2)WX-350
35	WX-350	(DWX-302	WX-350	(DWX-350 (2)WX-350	(2JWX-251	(3)WS-302
40	WX-350	(DWX-350 (2)WX-350	(2)WX-251	(3)WX-302	(2)WX-302	(DWX-302
						(2)WX-350

FIGURE 8.34 ■ Sizing and selection information for perssure tanks. (Courtesy of McGraw-Hill)

HOMES WITH 1 TO 11/2 BATHROOMS

Posted by admin on 17/ 11/ 15

We will start our sizing exercises with homes where less than two bathrooms are present. You will see tables for gas-fired, electric, and oil-fired water heaters. The number of bedrooms in our sample homes can range from one to three. You will have to use the chart to size a water heater for the examples given. Let’s start with a gas-fired water heater. The house we will size it for will have two bedrooms and one bathroom. What size water heater is needed (Fig. 7.1)?

All you have to do is scan the table for the answer to sizing question. Look under the heading for two bedrooms and run down to the column that lists storage. You will see that a 30-gallon water heater is the minimum size recommended for the application. You will also note that the water heater will recover fully in one hour. Personally, i’d probably up the size of the

Number of bedrooms	1	2	3
Storage capacity (gallons)	20	30	30
Input in Btuh	27,000	36,000	36,000
Draw (gallons per hour)	43	60	60
Recovery (gallons per hour)	23	30	30

FIGURE 7.1 ■ Water heating sizing table for gas heaters (minimum recommendations). Assume less than two full bathrooms.

Number of bedrooms	1	2	3
Storage capacity (gallons)	20	30	30
Input in Btuh	2.5 KW	3.5 KW	4.5 KW
Draw (gallons per hour)	30	44	58
Recovery (gallons per hour)	10	14	18

FIGURE 7.2 ■ Water heating sizing table for electric heaters (minimum recommendations). Assume less than two full bathrooms.

Number of bedrooms	1	2	3
Storage capacity (gallons)	30	30	30
Input in Btuh	70,000	70,000	70,000
Draw (gallons per hour)	89	89	89
Recovery (gallons per hour)	59	59	59

FIGURE 7.3 ■ Water heating sizing table for oil-fired heaters (minimum recommendations). Assume less than two full bathrooms.

heater to 40 gallons, but by code in my region, a 30-gallon tank is all that would be required.

Now, suppose we had the same house but wanted to put an electric water heater in it? What size would we use? Refer to the table in Figure 7.2 to find your answer. In this case, the storage capacity for an electric heater is the same as that required of a gas-fired heater. A 30-gallon tank is all that is needed. But, look at the recovery rate for the electric heater. It’s about half as good as the recovery rate for a gas heater. This could be good reason to upgrade the heater to something larger or more powerful.

Let’s consider an oil-fired water heater. The basic table (Fig. 7.3) is the same, in terms of use. Again, using the same scenario, what size oil-fired heater would be needed? You will find that a 30-gallon tank is, once again, adequate. Check out the recovery rate. It’s great. As you can see, sizing water heaters with the tables provided here is truly easy.

SIZING WATER HEATERS

Posted by admin on 17/ 11/ 15

izing water heaters is not a complicated process. It is, however, an important part of most plumbing jobs. Local code requirements call for minimum standards. The minimum facility requirements can be found in any major codebook or local code enforcement office. Since plumbing codes are regional, you will have to check your local code for exact requirements. But, the math that I’m about to show you will work in any location. Some of the numbers might be different, depending on code requirements, but the mathematical procedure will be the same.

When you figure the size of a water heater, remember that the codes offer suggestions and regulations for minimum requirements. The fact that a 40- gallon water heater will pass code may not mean that it is the best size heater for a given job. Use some common sense when sizing water heaters. Skimping on heater size can prove to be frustrating for your customers,- no one enjoys running out of hot water.

There are three types of water heaters that we will discuss. Oil-fired water heaters are the least common of the three. Depending upon where you work, you might find that gas-fired water heaters or electric water heaters are the most prevalent in your region. Overall, electric water heaters are more prolific than gas-fired heaters. Regardless of which type of water heaters you will be working with, you will find the following sizing information helpful.

129

ELEMENTS OF SIZING

Подпись: ✓ fast code fact Most codes require electric water heaters to have a disconnect box near the appliance and a number 10 electrical wire. In years past, a number 12 wire was acceptable, but this is rarely the case these days. Check your local code for electrical requirements and don’t replace or install a water heater that is not in compliance with current code requirements. Elements of sizing are something that you must understand, so let’s discuss what they are. The first element is the number of bathrooms in a home or building. When we move to the sizing charts in this chapter, you will see three different formats. This is due to the number of bathrooms. An additional element is the number of bedrooms found in a home. The number of bedrooms is very important. Of course, the storage size of a water heater is a key element. Other elements are the recovery rate, the draw, and the input in either British thermal units per hour (Btuh) or kilowatts (KW). i have prepared some sizing tables for you to use that will make your sizing efforts very easy. Let’s look at each table and do a few simple sizing examples to make sure you understand how to use the charts effectively.

ROOF DRAIN SIZING METHOD

Posted by admin on 17/ 11/ 15

B101 Sizing Example

The following example gives one method of sizing the primary drain system and sizing the scuppers in the parapet walls. This method converts the roof area to an equivalent roof area for a 4-inch rate of rainfall so that Fig. 6.9 can be used as printed.

B101.1 Problem: Given the roof plan in Fig. 6.13 and the site location in Birmingham, Alabama, size the primary roof drain system and size the scuppers, denoting the required head of water above the scupper for the structural engineer.

Note: For the purposes of this appendix the following metric conversions are applicable:

1 in = 25.4 mm 1 ft = 305 mm 1 ft2 = 0.0929 m2

1001-O’

ROOF DRAIN SIZING METHOD

FIGURE 6.13 ■ Example of a roof plan. (Courtesy of Standard Plumbing Code)

B101.2 Solution:

Step 1. From Fig. 6.11 the 100 year 60 minute precipitation is 3.75 inches per hour. Step 2. Each vertical drain must carry 2,500 sq ft of roof area at 3.75 inches per hour of rainfall. To convert to an area for a 4 inch per hour rainfall to enter Fig. 6.9 do this:

2.500 x 3.75 – e 4 — 2,344 sq ft. Enter Fig. 6.9 until you find a diameter pipe that will carry 2,344 sq ft. A minimum 4-inch vertical drain is required.

Step 3. Horizontal Drain 2,500 sq ft

To convert to an area for use in Fig. 6.9 do this:

2.500 X 3.75 H = 2,344 sq ft

Enter Fig. 6.9 until you find a diameter pipe that will carry 2,344 sq ft. A minimum 4-inch diameter pipe with a ‘A inch per foot slope will carry 2,650 sq ft. A minimum 4-inch diameter drain on a V* inch per foot slope is required.

Step 4. Horizontal Drain

5.0 sq ft

To convert to an area for use in Fig. 6.9 do this:

5.0 x 3.75 – e 4 = 4,688 sq ft.

Enter Table 1108.2 until you find a diameter pipe that will carry 4,688 sq ft. A 5-inch diameter pipe with a V* inch per foot slope will carry 4,720 sq ft. A minimum 5-inch diameter drain on a ‘A inch per foot slope is required.

Step 5. Horizontal Drain

10.0 sq ft

To convert to an area for use in Fig. 6.9 do this:

10.0 x 3.75 + 4 = 9,375 sq ft

Enter Fig. 6.9 until you find a diameter pipe that will carry 9,375 sq ft. An 8- inch diameter pipe on 1.4 inch per foot slope will carry 16,300 sq ft but a 6-inch will carry only 7,550 sq ft, therefore, use an 8-inch diameter drain on a V«inch per foot slope.

Step 6. From Fig. 6.12 the rate caused by a 100 year 15 minute precipitation is 7.2 inches per hour. The scuppers must be sized to carry the flow caused by a rain fall rate of 7.2 inches per hour.

Step 7. Each scupper is draining 2,500 sq ft of roof area. To convert this roof area to an area for use with Fig. 6.15 do this:

2.500 X 7.2 – E 4 = 4,500 sq ft

FIGURE 6.14 ■ Rainwater sizing example. (Courtesy of Standard Plumbing Code)

Enter Fig. 6.15 to find a length (see Fig. 6.15) and head that will carry 4,500 sq ft or more.

From Fig. 6.15 a 12-inch wide weir with a 4-inch head carries 6,460 sq ft.

Use 12-inch wide x 5-inch high scuppers at four locations.

A height of 5 inches is needed to assure an open area above the 4-inch head.

Step 8. Notify the structural engineer that the design of the roof structure must account for a height of water to the scupper entrance elevation plus 4 inches for the required head to cause design flow.

inches	4	6	8	12	16	20	24
1	273	418	562	851	1,139	1,427	1,715
2	734	1,141	1,549	2,365	3,180	3,996	4,813
3	1,274	2,023	2,772	4,270	5,768	7,267	8,766
4	1,845	2,999	4,152	6,460	8,766	11,073	13,381
6	2,966	5,087	7,204	11,442	15,680	19,918	24,160

Note:

Table based on rainfall of 4 inches per hour.

FIGURE 6.15 ■ Scupper sizing table roof area (sq ft.). (Courtesy of Standard Plumbing Code)

ROOF DRAIN SIZING METHOD

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STORM-WATER CALCULATIONS

Posted by admin on 16/ 11/ 15

Подпись: ✓ fast code fact Journeyman plumbers are not normally required to know how to figure roof drains and major storm-water calculations. This is typically the job of a master plumber. Of course, circumstances vary from location to location, so the process is well worth learning at any level in your plumbing career. Storm-water calculations stump some plumbers. I think that the problem for some plumbers is computing the amount of water accumulated due to structures on roofs. For example, if a roof has an enclosed stairway system, the walls and roof of the stairway have to be factored into the equation for what is required in rainfall drainage. Some plumbers find doing the math for roof drains, rain leaders, and other storm piping to be intimidating. Given the proper charts and tables, the job is not really too difficult.

Подпись: been there done that Don’t allow the code requirements to scare you. I remember the first time I had to pipe an island sink. It made me very uncomfortable, even though there was a diagram in the codebook on how to do the job. What may seem daunting when you first look at the code is not necessarily such a mess. Trust in yourself. I used to teach code classes for plumbers who were preparing to take their licensing tests. After teaching the class for a while, I noticed some common elements from class to class. One common thread that seemed to run from class to class was a fear of doing storm-water calculations. I came to expect the classes to be intimidated by what I didn’t perceive to be any big deal. Knowing how to size a drainage system for storm water is a requirement for licensing where I live and work, so the people in the class had to address their fears. This, however, was true only of those going for their master’s license. Oddly enough, once they were given an example or two of how the work is done, most of them didn’t have any problem with their calculations.

111

STORM-WATER CALCULATIONS

FIGURE 6.1 ■ Rainwater code requirements. (Courtesy of Uniform Plumbing Code)

I could create some examples for you to work with here, but I won’t. Why? Because two of the major codes already offer sample exercises in their codebooks, and the two codes have agreed to allow me to use their examples for this chapter’s tutorial. So, what I’m going to do is show you actual excerpts from two codebooks. One of the codes is the Uniform Plumbing Code. The other is the Standard Plumbing Code, or as some people call it, the Southern Plumbing Code. I will let you look over the examples, one at a time, and then I will comment on them, pointing out some of the areas that may appear a little tricky. Let’s start with the example provided in the Uniform Plumbing Code. Please refer to Figures 6.1 through 6.8 for code requirements and a sizing example for rainwater systems. I want you to keep in mind that books age

(c) Roof drains, overflow drains, and rainwater piping installed within the construction of the building shall be tested in conformity with the provisions of this Code for testing drain, waste, and vent systems.

Part В
Roof Drains

A 2 Materials: Roof drains shall be of cast iron, copper, lead, or other corrosion resisting material.

A 2.1 Strainers:

(a) Roof drains shall be equipped with strainers extending not less than four (4) inches (101.6 mm) above the surface of the roof immediately adjacent to the drain. Strainers shall have minimum inlet area one and one-half (IV2) times the pipe to which it is connected.

(b) Roof deck strainers for use on sun decks, parking decks, and similar occupied areas may be of an approved flat-surface type which is level with the deck. Such drains shall have an inlet area not less than two (2) times the area of the pipe to which the drain is connected.

(c) Roof drains passing through the roof into the interior of a building shall be made watertight at the roof line by the use of a suitable flashing material.

PartC

Sizing of Rainwater Piping

A 3.1 Vertical rainwater piping shall be sized in accordance with Fig. 8.3. Figure 8.3 is based upon maximum inches (mm) of rainfall per hour falling upon a given roof area in square feet (m2). Consult local rainfall figures to determine maximum rainfall per hour.

A 3.2 Vertical Wall Areas. Where vertical walls project above a roof so as to permit storm water to drain to the roof area below the adjacent roof area may be computed from Fig. 8.3 as follows:

(a) For one (1) wall—add fifty (50) percent of the wall area to the roof area figures.

(b) For two (2) adjacent walls—add thirty-five (35) percent of the total wall areas.

(d) Two (2) walls opposite of differing heights—add fifty (50) percent of wall area above top of lower wall.

(e) Walls on three (3) sides—add fifty (50) percent of area of the inner wall below the top of the lowest wall, plus allowance for area of wall above top of lowest wall per (b) and (d).

(f) Walls on four (4) sides—no allowance for all areas below top of lowest wall – add for areas above top of lowest wall per (a), (b), (d), and (e).

FIGURE 6.2 ■ Rainwater code requirements. (Courtesy of Uniform Plumbing Code)

and the illustrations here may not be up to speed with your current, local code. Check you own code requirements and use the tables here as examples of how to use what you have.

Now that you’ve had a chance to look over the illustrations, you may have a solid understanding of how to size a rainwater system. If you do, that’s great. But, maybe you have a little confusion that needs to be cleared up. Let me go over a few of the points that some plumbers from my classes have had trouble with. Start by looking at Figure 6.2, part C. In category A 3.2 of Figure 6.2, I want you to look at letter A. The code tells you to figure 50 percent of

a single wall for additional rainwater. So, if the wall is 10 feet long and 10 feet tall, its total area would be 100 square feet. This is determined by multiplying the width by the height. In this case, we would add 50 square feet of area to our working numbers to apply to the sizing chart.

Now look at the ruling in letter B. It says that if you have two adjacent walls, you must add 35-percent of their combined area to the equation.

Sizing of Roof Drains and Rainwater Piping for Varying Rainfall Quantities are Horizontal Projected Roof Areas in Square Feet

Rain fall		Size of drain or	leader in	inches*
in inches	2	3	4	5	6	8
1	2880	8800	18400	34600	54000	116000
2	1440	4400	9200	17300	27000	58000
3	960	2930	6130	11530	17995	38660
4	720	2200	4600	8650	13500	29000
5	575	1760	3680	6920	10800	23200
6	480	1470	3070	5765	9000	19315
7	410	1260	2630	4945	7715	16570
8	360	1100	2300	4325	6750	14500
9	320	980	2045	3845	6000	12890
10	290	880	1840	3460	5400	11600
11	260	800	1675	3145	4910	10545
12	240	730	1530	2880	4500	9660

_ . . Size of drain or leader in millimeters*

in mm	50.8	76.2	101.6	127	152.4	203.2
25.4	267.6	817.5	1709.4	3214.3	5016.6	10776.4
50.8	133.8	408.8	854.7	1607.2	2508.3	5388.2
76.2	89.2	272.2	569.5	1071,1	1671.7	3591.5
101.6	66.9	204.4	427.3	803.6	1254.2	2694.1
127	53.4	163.5	341.8	642.9	1003.3	2155.3
152.4	44.6	136.6	285.2	535.6	836.1	1794.4
177.8	38.1	117.1	244.3	459.4	716.7	1539.4
203.2	33.4	102.2	213.7	401.8	627.1	1347.1
228.6	29.7	91	190	357.2	557.4	1197.5
254	26.9	81.8	170.9	321.4	501.7	1077.6
279.4	24.2	74.3	155.6	292.2	456.1	979.6
304.8	22.3	67.8	142.1	267.6	418.1	897.4

Подпись: A 3.3 Horizontal Rainwater Piping. The size of a building rainwater piping or any of its horizontal branches shall be sized in accordance with Figs. 8,5 and 8.6 (based upon maximum roof areas to be drained). Example: Figs. 8.5 and 8.6 Roof Area —5900 sq. ft. (548.1 m2) Max. Rainfall/hr. —5 inches (127 mm) Pipe Laid at Vi" (20.9 mm/m) slope Find roof area in column under 5" (127 mm) rainfall (6040 sq. ft. (561.1 m2) is closest), read 6" (152.4 mm) as size of piping in left hand column. A 3.4 Roof Gutter. The size of semi-circular roof gutters shall be based on the maximum roof area, in accordance with Figs. 8.7 and 8.8.

Подпись: Example: Figs. 8.7 and 8.8 Roof Area—2000 sq. ft. (186 m2) Max. Rainfall/hr.—4" (101.6 mm) Gutter set at Vs" (10.4 mm/m) slope Find roof area in column under 4" (101.6 mm) rainfall 1950 sq. ft. (181.4 m2) is closest), read 7" (177.8 mm) diameter gutter in left hand column. A 3.5 If the rainfall is more or less than those shown in Figs. 8.5-8.8, then adjust the figures in the 2" (50.8 mm) rainfall column by multiplying by two (2) and dividing by the maximum rate of rainfall in inches/hr. (mm/hour). Example: In Figs. 8.5 and 8,6 with an Ve" (10.4 mm/m) slope and an 8" (203.2 mm) rainfall, find the number of square feet (m2) a 4" (101,6 mm) pipe will carry. 2 X 3760 „ = 940 sq. ft. (87.4 m2)

Assuming that each wall was 10 feet by 10 feet, we would have a total of 200 square feet. 35 percent of 200 square feet is 70 square feet. See how easy this is? In the rulings identified by the letter C, you can see that no additional square footage is added when you have two walls that are opposite of each other and that are the same size. But, letter D offers another ruling. Assume that you have two walls opposite of each other. one of the walls is 10 feet by 10 feet. The other is 10 feet by 15 feet. How much area do you add? One wall is 5 feet taller than the other and 10 feet wide. This amounts to a total area of 50 square feet in differing size for computation purposes. Now all you have to do is divide the difference in half for your working number, which in this case would be 25 square feet. If you pay attention, the code does most of the work for you.

Size of Horizontal Rainwater Piping

Size of pipe in mm 10.4 mm/m slope	Maximum rainfall	in millimeters per	hour
50.8	76.2	101.6	127	152.4
76.2	152.7	101.8	76.4	61	50.9
101.6	349.3	232.8	174.7	139.7	116.4
127	620.6	413.7	310.3	248.2	206.9
152.4	994	662.7	497	397.6	331.3
203.2	2136.7	1424.2	1068.4	854.7	706
254	3846.1	2564	1923	1540.3	1282
279.4	6187.1	4124.8	3093.6	2475.8	2062.4
381	10126.1	6763.1	5527.6	4422	3683.5

Size of pipe in mm 20.9 mm/m slope	Maximum rainfall in millimeters per hour
50.8	76.2	101.6	127	152.4
76.2	215.5	143.6	107.8	86.2	71.8
101.6	492.4	328.2	246.2	197	164.1
127	877	584.1	438.5	350.8	292.3
152.4	1402.8	935.1	701.4	561.1	467.6
203.2	3028.5	2019	1514.3	1211.4	1009.5
254	5425.4	3618.5	2712.7	2169.2	1806.9
304.8	8732.6	5815.5	4366.3	3493	2912.4
381	15607.2	10404.8	7803.6	6247.5	5205.4

Size of pipe in mm 41.7 mm/m slope	Maximum rainfall	in millimeters per hour
50.8	76.2	101.6	127	152.4
76.2	305.5	213.2	152.7	121.7	101.8
101.6	698.6	465.4	349.3	279.6	232.3
127	1241.1	826.8	620.6	494.2	413.4
152.4	1988.1	1272.3	994	797.1	663.3
203.2	4274.4	2847.4	2136.7	1709.4	1423.2
254	7692.1	5128.1	3846.1	3079.6	2564
304.8	12374.3	8249.5	6187.1	4942.3	4124.8
381	22110.2	14752.5	11055.1	8853.4	7362.3

Size of Gutters

Maximum rainfall in inches per hour

Уїв" slope	2	3	4	5	6
3	340	226	170	136	113
4	720	480	*360	288	240
5	1250	834	625	500	416
6	1920	1280	960	768	640
7	2760	1840	1380	1100	918
8	3980	2655	1990	1590	1325
10	7200	4800	3600	2880	2400
Diameter of gutter Vb" slope	Maximum rainfall in inches per	hour
2	3	4	5	6
3	480	320	240	192	160
4	1020	681	510	408	340
5	1760	1172	880	704	587
6	2720	1815	1360	1085	905
7	3900	2600	1950	1560	1300
8	5600	3740	2800	2240	1870
10	10200	6800	5100	4080	3400
Diameter of gutter slope	Maximum rainfall in inches per	hour
2	3	4	5	6
3	680	454	340	272	226
4	1440	960	720	576	480
5	2500	1668	1250	1000	834
6	3840	2560	1920	1536	1280
7	5520	3680	2760	2205	1840
8	7960	5310	3980	3180	2655
10	14400	9600	7200	5750	4800
Diameter of gutter W slope	Maximum rainfall in inches per	hour
2	3	4	5	6
3	960	640	480	384	320
4	2040	1360	1020	816	680
5	3540	2360	1770	1415	1180
6	5540	3695	2770	2220	1850
7	7800	5200	3900	3120	2600
8	11200	7460	5600	4480	3730
10	20000	13330	10000	8000	6660

Size of Gutters

Diameter of gutter 20.9 mm/m slope	Maximum rainfall	in millimeters per hour
50.8	76.2	101.6	127	152.4
76.2	63.2	42.2	31.6	25.3	21
101.6	133.8	89.2	66.9	53.5	44.6
127	232.3	155	116.1	92.9	77.5
152.4	356.7	237.8	178.4	142.7	118.9
177.8	512.8	341.9	256.4	204.9	170.9
203.2	739.5	493.3	369.7	295.4	246.7
254	133.8	891.8	668.9	534.2	445.9

Diameter of gutter 41.7 mm/m slope	Maximum rainfall	in millimeters per	hour
50.8	76.2	101.6	127	152.4
76.2	89.2	59.5	44.6	35.7	29.7
101.6	189.5	126.3	94.8	75.8	63.2
127	328.9	219.2	164.4	131.5	109.6
152.4	514.7	343.3	257.3	206.2	171.9
177.8	724.6	483.1	362.3	289.9	241.4
203.2	1040.5	693	520.2	416.2	346.5
254	1858	1238.4	929	743.2	618.7

Now, let’s look at the example given by the Standard Plumbing Code (Figs. 6.9 to 6.15). Some plumbing codes have recently joined forces to create a cohesive code. Most of this book is based on the International Plumbing Code, but there are others and there are combinations. Keep in mind that every code jurisdiction can create their own amendments to the code, so you must refer to your local, enforceable code to be sure that you are on track with local requirements.

STORM-WATER CALCULATIONS

The sizing example you have just seen is a good, step-by-step example of how to size a drainage system for storm water. You’ve seen actual code examples and rulings, but remember that these codes are subject to change and may not be the codes being used in your area. Consult your local plumbing code for current, applicable code requirements in your region.

SECONDARY (EMERGENCY) ROOF DRAINS Secondary Drainage Required

Secondary (emergency) roof drains or scuppers shall be provided where the roof perimeter construction extends above the roof in such a manner that water would be entrapped should the primary drains allow buildup for any reason.

Separate Systems Required

Secondary roof drain systems shall have piping and point of discharge separate from the primary system. Discharge shall be above grade in a location which would normally be observed by the building occupants or maintenance personnel.

Maximum Rainfall Rate for Secondary Drains

Secondary (emergency) roof drain systems or scuppers shall be sized based on the flow rate caused by the 100 year 15 minute precipitation as indicated in Fig. 8.12. The flow through the primary system shall not be considered when sizing the secondary roof drain system.

CONVERSION OF ROOF AREA

General

Where roof drainage is connected to a combined sewer, the drainage area may be converted to equivalent fixture unit loads.

Less Than 256 Fixture Units

When the total fixture unit load on the combined drain is less than 256 fixture units, the equivalent drainage area in horizontal projection shall be taken as 1000 sq ft (92.9 m2).

Greater Than 256 Fixture Units

When the total fixture unit load exceeds 256 fixture units, each additional fixture unit shall be considered the equivalent of 3.9 ft2 (0.3623 m2) of drainage area.

Rainfall Other Than 4 Inches (102 mm) Per Hour

If the rainfall to be provided for is more or less than 4 inches (102 mm) per hour, the 1,000 sq ft (92.9 m2) equivalent in 1110.2 and the 3.9 sq ft (0.3623 m2) in 1110.3 shall be adjusted by multiplying by 4 and dividing by the rainfall per hour to be provided for.

VALUES FOR CONTINUOUS FLOW

Where there is a continuous or semicontinuous discharge into the building storm drain or building storm sewer, as from a pump, ejector, air conditioning plant, or similar device, each gallon per minute of such discharge shall be computed as being equivalent to 24 sq ft (2.23 m2) of roof area, based upon a 4-inch (102 mm) rainfall.

FIGURE 6.10A ■ Rainwater code requirements. (Courtesy of Standard Plumbing Code)

BACKWATER VALVES

Fixture Branches

Backwater valves shall be installed in the branch of the building drain which receives only the discharge from fixtures located within such branch and shall be located below grade.

Material

Backwater valves shall have all bearing parts of corrosion resistant material. Backwater valves shall comply with ANSI/ASME A112.14.1 or CSA B181.1, CSAB181.2.

Seal

Backwater valves shall be so constructed as to insure a mechanical seal against backflow.

Diameter

Backwater valves, when fully opened, shall have a capacity not less than that of the pipes in which they are installed.

Location

Backwater valves shall be so installed to be accessible for service and repair. APPENDIX REFERENCES

Additional provisions for storm drainage are found in Appendix В-Roof Drain Sizing Method. These provisions are applicable only where specifically included in the adopting ordinance.

FIGURE 6.10B ■ Rainwater code requirements. (Courtesy of Standard Plumbing Code)

STORM-WATER CALCULATIONS