610.10 Sizing for Flushometer Valves

Where using Table 610.4 to size water supply systems serving flushometer valves, the number of flushometer fixture units assigned to every section of pipe, whether branch or main, shall be determined by the number and category of flushometer valves served by that section of pipe, in accordance with Table 610.10. Piping supplying a flushometer valve shall be not less in size than the valve inlet.

Where using Table 610.10 to size water piping, care shall be exercised to assign flushometer fixture units based on the number and category of fixtures served.

TABLE 610.10 FLUSHOMETER FIXTURE UNITS FOR WATER SIZING USING TABLE 610.3
FIXTURE CATEGORY: WATER CLOSET WITH FLUSHOMETER VALVES
NUMBER OF FLUSHOMETER VALVES	INDIVIDUAL FIXTURE UNITS ASSIGNED IN DECREASING VALUE	FIXTURE UNITS ASSIGNED FOR WATER CLOSETS AND SIMILAR 10-UNIT FIXTURES IN ACCUMULATIVE VALUES
1	40	40
2	30	70
3	20	90
4	15	105
5 or more	10 each	115 plus 10 for each additional fixture in excess of 5
FIXTURE CATEGORY: URINALS WITH FLUSHOMETER VALVES
NUMBER OF FLUSHOMETER VALVES	INDIVIDUAL FIXTURE UNITS ASSIGNED IN DECREASING VALUE	FIXTURE UNITS ASSIGNED FOR URINALS AND SIMILAR 5-UNIT FIXTURES IN ACCUMULATIVE VALUES
1	20	20
2	15	35
3	10	45
4	8	53
5 or more	5 each	58 plus 5 for each additional fixture in excess of 5

TABLE 610.3 WATER SUPPLY FIXTURE UNITS (WSFU) AND MINIMUM FIXTURE BRANCH PIPE SIZES [3]

APPLIANCES, APPURTENANCES OR FIXTURES2	MINIMUM FIXTURE BRANCH PIPE SIZE1,4 (inches)	PRIVATE	PUBLIC	ASSEMBLY6
Bathtub or Combination Bath/Shower (fill)	1⁄2	4.0	4.0	––
3⁄4 inch Bathtub Fill Valve	3⁄4	10.0	10.0	––
Bidet	1⁄2	1.0	––	––
Clothes Washer	1⁄2	4.0	4.0	––
Dental Unit, cuspidor	1⁄2	––	1.0	––
Dishwasher, domestic	1⁄2	1.5	1.5	––
Drinking Fountain or Water Cooler	1⁄2	0.5	0.5	0.75
Hose Bibb	1⁄2	2.5	2.5	––
Hose Bibb, each additional8	1⁄2	1.0	1.0	––
Lavatory	1⁄2	1.0	1.0	1.0
Lawn Sprinkler, each head5	––	1.0	1.0	––
Mobilehome or Manufactured Home, each (minimum)9	––	6.0	––	––
Sinks	––	––	––	––
Bar	1⁄2	1.0	2.0	––
Clinical Faucet	1⁄2	––	3.0	––
Clinical Flushometer Valve with or without faucet	1	––	8.0	––
Kitchen, domestic with or without dishwasher	1⁄2	1.5	1.5	––
Laundry	1⁄2	1.5	1.5	––
Service or Mop Basin	1⁄2	1.5	3.0	––
Washup, each set of faucets	1⁄2	––	2.0	––
Shower, per head	1⁄2	2.0	2.0	––
Urinal, 1.0 GPF Flushometer Valve	3⁄4	See Footnote7	See Footnote7	––
Urinal, greater than 1.0 GPF Flushometer Valve	3⁄4	See Footnote7	See Footnote7	––
Urinal, flush tank	1⁄2	2.0	2.0	3.0
Nonwater Urinal with Drain Cleansing Action	1⁄2	1.0	1.0	1.0
Wash Fountain, circular spray	3⁄4	––	4.0	––
Water Closet, 1.6 GPF Gravity Tank	1⁄2	2.5	2.5	3.5
Water Closet, 1.6 GPF Flushometer Tank	1⁄2	2.5	2.5	3.5
Water Closet, 1.6 GPF Flushometer Valve	1	See Footnote7	See Footnote7	––
Water Closet, greater than 1.6 GPF Gravity Tank	1⁄2	3.0	5.5	7.0
Water Closet, greater than 1.6 GPF Flushometer Valve	1	See Footnote7	See Footnote7	––

For SI units: 1 inch = 25 mm

Notes: 1 Size of the cold branch pipe, or both the hot and cold branch pipes. 2 Appliances, appurtenances, or fixtures not referenced in this table shall be permitted to be sized by reference to fixtures having a similar flow rate and frequency of use. 3 The listed fixture unit values represent their load on the cold water building supply. The separate cold water and hot water fixture unit value for fixtures having both hot and cold water connections shall be permitted to be each taken as three-quarter of the listed total value of the fixture. 4 The listed minimum supply branch pipe sizes for individual fixtures are the nominal (I.D.) pipe size. 5 For fixtures or supply connections likely to impose continuous flow demands, determine the required flow in gallons per minute (gpm) (L/s), and add it separately to the demand in gpm (L/s) for the distribution system or portions thereof. 6 Assembly [Public Use (See Table 422.1)]. 7 Where sizing flushometer systems, see Section 610.10. 8 Reduced fixture unit loading for additional hose bibbs is to be used where sizing total building demand and for pipe sizing where more than one hose bibb is supplied by a segment of water distribution pipe. The fixture branch to each hose bibb shall be sized on the basis of 2.5 fixture units. 9 For water supply fixture unit values related to lots within mobilehome parks in all parts of the State of California, see California Code of Regulations, Title 25, Division 1, Chapter 2, Article 5, Section 1278. For water supply fixture unit values related to lots within special occupancy parks in all parts of the State of California, see California Code of Regulations, Title 25, Division 1, Chapter 2.2, Article 5, Section 2278.

		TABLE 610.4 FIXTURE UNIT TABLE FOR DETERMINING WATER PIPE AND METER SIZES
METER AND STREET SERVICE (inches)	BUILDING SUPPLY AND BRANCHES (inches)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)	MAXIMUM ALLOWABLE LENGTH (feet)
METER AND STREET SERVICE (inches)	BUILDING SUPPLY AND BRANCHES (inches)	40	60	80	100	150	200	250	300	400	500	600	700	800	900	1000
PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1	PRESSURE RANGE – 30 to 45 psi1
3⁄4	1⁄22	6	5	4	3	2	1	1	1	0	0	0	0	0	0	0
3⁄4	3⁄4	16	16	14	12	9	6	5	5	4	4	3	2	2	2	1
3⁄4	1	29	25	23	21	17	15	13	12	10	8	6	6	6	6	6
1	1	36	31	27	25	20	17	15	13	12	10	8	6	6	6	6
3⁄4	11⁄4	36	33	31	28	24	23	21	19	17	16	13	12	12	11	11
1	11⁄4	54	47	42	38	32	28	25	23	19	17	14	12	12	11	11
11⁄2	11⁄4	78	68	57	48	38	32	28	25	21	18	15	12	12	11	11
1	11⁄2	85	84	79	65	56	48	43	38	32	28	26	22	21	20	20
11⁄2	11⁄2	150	124	105	91	70	57	49	45	36	31	26	23	21	20	20
2	11⁄2	151	129	129	110	80	64	53	46	38	32	27	23	21	20	20
1	2	85	85	85	85	85	85	82	80	66	61	57	52	49	46	43
11⁄2	2	220	205	190	176	155	138	127	120	104	85	70	61	57	54	51
2	2	370	327	292	265	217	185	164	147	124	96	70	61	57	54	51
2	21⁄2	445	418	390	370	330	300	280	265	240	220	198	175	158	143	133
PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1	PRESSURE RANGE – 46 to 60 psi1
3⁄4	1⁄22	7	7	6	5	4	3	2	2	1	1	1	0	0	0	0
3⁄4	3⁄4	20	20	19	17	14	11	9	8	6	5	4	4	3	3	3
3⁄4	1	39	39	36	33	28	23	21	19	17	14	12	10	9	8	8
1	1	39	39	39	36	30	25	23	20	18	15	12	10	9	8	8
3⁄4	11⁄4	39	39	39	39	39	39	34	32	27	25	22	19	19	17	16
1	11⁄4	78	78	76	67	52	44	39	36	30	27	24	20	19	17	16
11⁄2	11⁄4	78	78	78	78	66	52	44	39	33	29	24	20	19	17	16
1	11⁄2	85	85	85	85	85	85	80	67	55	49	41	37	34	32	30
11⁄2	11⁄2	151	151	151	151	128	105	90	78	62	52	42	38	35	32	30
2	11⁄2	151	151	151	151	150	117	98	84	67	55	42	38	35	32	30
1	2	85	85	85	85	85	85	85	85	85	85	85	85	85	83	80
11⁄2	2	370	370	340	318	272	240	220	198	170	150	135	123	110	102	94
2	2	370	370	370	370	368	318	280	250	205	165	142	123	110	102	94
2	21⁄2	654	640	610	580	535	500	470	440	400	365	335	315	285	267	250
PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1	PRESSURE RANGE – Over 60 psi1
3⁄4	1⁄22	7	7	7	6	5	4	3	3	2	1	1	1	1	1	0
3⁄4	3⁄4	20	20	20	20	17	13	11	10	8	7	6	6	5	4	4
3⁄4	1	39	39	39	39	35	30	27	24	21	17	14	13	12	12	11
1	1	39	39	39	39	38	32	29	26	22	18	14	13	12	12	11
3⁄4	11⁄4	39	39	39	39	39	39	39	39	34	28	26	25	23	22	21
1	11⁄4	78	78	78	78	74	62	53	47	39	31	26	25	23	22	21
11⁄2	11⁄4	78	78	78	78	78	74	65	54	43	34	26	25	23	22	21
1	11⁄2	85	85	85	85	85	85	85	85	81	64	51	48	46	43	40
11⁄2	11⁄2	151	151	151	151	151	151	130	113	88	73	51	51	46	43	40
2	11⁄2	151	151	151	151	151	151	142	122	98	82	64	51	46	43	40
1	2	85	85	85	85	85	85	85	85	85	85	85	85	85	85	85
11⁄2	2	370	370	370	370	360	335	305	282	244	212	187	172	153	141	129
2	2	370	370	370	370	370	370	370	340	288	245	204	172	153	141	129
2	21⁄2	654	654	654	654	654	650	610	570	510	460	430	404	380	356	329

For SI units: 1 inch = 25 mm, 1 foot = 304.8 mm, 1 pound-force per square inch = 6.8947 kPa

Notes: 1 Available static pressure after head loss. 2 Building supply, not less than 3 ⁄ 4 of an inch (20 mm) nominal size.

In the example below, fixture units assigned to each section of pipe are computed. Each capital letter refers to the section of pipe above it unless otherwise shown.

LAV LAV UR UR WC WC

F E D C B A V LAV UR UR WC WC G H I J K L M LAV UR WC LAV UR W S R Q P O N T
T G H I J K L	T G H I J K L
T G H I J K L	S R Q P O N

A: 1 WC = 40 F.U.

B: 2 WC = 70 F.U.

C: 2 WC (70) + 1 UR (20) = 90 F.U.

D: 2 WC (70) + 2 UR (35) = 105 F.U.

E: 2 WC (70) + 2 UR (35) + 1 LAV (1) = 106 F.U.

F: 2 WC (70) + 2 UR (35) + 2 LAV (2) = 107 F.U.

G: 1 LAV = 1 F.U.

H: 2 LAV = 2 F.U.

I: 2 LAV (2) + 1 UR (20) = 22 F.U.

J: 2 LAV (2)+ 2 UR (35) = 37 F.U.

K: 2 LAV (2) + 2 UR (35) + 1 WC (40) = 77 F.U.

L: 2 LAV (2) + 2 UR (35) + 2 WC (70) = 107 F.U.

M: 4 WC (105) + 4 UR (53) + 4 LAV (4) = 162 F.U.

N: 1 WC = 40 F.U.

O: 1 WC (40) + 1 UR (20) = 60 F.U.

P: 1 WC (40) + 1 UR (20) + 1 LAV (1) = 61 F.U.

Q: 2 WC (70) + 1 UR (20) + 1 LAV (1) = 91 F.U.

R: 2 WC (70) + 2 UR (35) + 1 LAV (1) = 106 F.U.

S: 2 WC (70) + 2 UR (35) + 2 LAV (2) = 107 F.U.

T: 6 WC (125) + 6 UR (63) + 6 LAV (6) = 194 F.U.

LAV LAV UR UR WC WC

EXAMPLE 610.10

SIZING METHOD FOR PUBLIC USE FIXTURES

USING TABLE 610.10

610.10 Sizing for Flushometer Valves — 2025 California Plumbing Code

Explained in plain English