A.O. Smith BT- 65 warranty Purging, Gas Pressure Regulator, Cubic Feet Per Hour

TABLE 1 - GAS SUPPLY LINE SIZES (IN INCHES)*

MAXIMUM CAPACITY OF PIPE IN

CUBIC FEET PER HOUR

LENGTH			NORMAL IRON PIPE SIZES (INCHES)
IN			INPUT IN THOUSANDS BTU/HR
FEET	1/2"	3/4"	1"	1 1/4"	1 1/2"	2"	2 1/2"	3"	4"
10	175	360	680	1400	2100	3960	6300	11000	23000
20	120	250	485	950	1460	2750	4360	7700	15800
30	97	200	375	770	1180	2200	3520	6250	12800
40	82	170	320	660	990	1900	3000	5300	10900
50	73	151	285	580	900	1680	2650	4750	9700
60	66	138	260	530	810	1520	2400	4300	8800
70	61	125	240	490	750	1400	2250	3900	8100
80	57	118	220	460	690	1300	2050	3700	7500
90	53	110	205	430	650	1220	1950	3450	7200
100	50	103	195	400	620	1150	1850	3250	6700
125	44	93	175	360	550	1020	1650	2950	6000
150	40	84	160	325	500	950	1500	2650	5500
175	37	77	145	300	460	850	1370	2450	5000
200	35	72	135	280	430	800	1280	2280	4600

LENGTH			NORMAL IRON PIPE SIZES (INCHES)
IN			INPUT IN KW
METERS	1/2"	3/4"	1"	1 1/4"	1 1/2"	2"	2 1/2"	3"	4"
3	51	105	199	410	615	1160	1845	3221	6735
6	35	73	142	278	428	805	1277	2255	4626
9	28	59	110	225	346	644	1031	1830	3748
12	24	50	94	193	290	556	878	1552	3192
15	21	44	83	170	264	492	776	1391	2840
18	19	40	76	155	237	445	703	1259	2577
21	18	37	70	143	220	410	659	1142	2372
24	17	35	64	135	202	381	600	1083	2196
27	16	32	60	126	190	357	571	1010	2108
31	15	30	57	117	182	337	542	952	1962
38	13	27	51	105	161	299	483	864	1757
46	12	25	47	95	146	278	439	776	1610
53	11	23	42	88	135	249	401	717	1464
61	10	21	40	82	126	234	375	688	1347

PRESSURE TESTING EXCEEDING 1/2 PSIG (3.45 Kpa). GAS SUPPLY LINE MUST BE CAPPED WHEN DISCONNECTED FROM THE HEATER. FOR TEST PRESSURES OF 1/2 PSIG (3.45 Kpa) OR LESS THE APPLIANCE NEED NOT BE DISCONNECTED, BUT MUST BE ISOLATED FROM THE SUPPLY PRESSURE TEST BY CLOSING THE MANUALGAS Shut-off VALVE.

PURGING

Gas line purging is required with new piping or systems in which air has entered.

CAUTION

PURGING SHOULD BE PERFORMED BY PERSONS EXPERIENCED IN THIS TYPE GAS SERVICE. TO AVOID RISK OF FIRE OR EXPLOSION, PURGE DISCHARGE MUST NOT ENTER CONFINED AREAS OR SPACES WHERE IGNITION CAN OCCUR. THE AREA MUST BE WELL VENTILATED AND ALL SOURCES OF IGNITION MUST BE INACTIVATED OR REMOVED.

GAS METER SIZE — NATURAL GAS ONLY

Be sure the gas meter has sufficient capacity to supply the full rated gas input of the water heater as well as the requirements of all other gas fired equipment supplied by the meter. If gas meter is too small, ask the gas company to install a larger meter having adequate capacity.

To prevent damage, care must be taken not to apply too much torque when attaching gas supply pipe to gas valve inlet.

Apply joint compounds (pipe dope) sparingly and only to the male threads of pipe joints. Do not apply compounds to the first two threads. Use compounds resistant to the action of liquefied petroleum gases.

BEFORE PLACING THE HEATER IN OPERATION, CHECK FOR GAS LEAKAGE. Use soap and water solution or other material acceptable for the purpose in locating the leaks. DO NOT USE MATCHES, CANDLES, FLAME OR OTHER SOURCES OF IGNITION FOR THIS PURPOSE.

FIGURE 4 - GAS PIPING AND DIRT LEG INSTALLATION

DISCONNECT THE HEATERAND ITS MANUALGAS Shut-off VALVE FROM THE GAS SUPPLY PIPING SYSTEM DURING ANY SUPPLY

FIGURE 5 -THERMOSTAT FOR NATURAL GAS

GAS PRESSURE REGULATOR

The gas pressure regulator is built into the gas valve and is equipped to operate on the gas specified on model and rating plate. The regulator is factory adjusted to deliver gas to burner at correct water column pressure allowing for a nominal pressure drop through the controls.

The minimum gas supply pressure for input adjustment is 5.0" W.C. (1.24 kPa) for natural gas or 11.0" W.C. (2.74 kPa) for propane gas.

Do not subject the combination gas valve to inlet gas pressures of more than 10.5" W.C. (2.61 kPa) - natural gas or 13.0" W.C. (3.23 kPa) - propane gas. A service regulator is necessary if higher gas pressures are encountered.

Gas pressure specified in Table 2, refer to flow pressure taken at pressure tap of automatic gas valve while heater is operating.

8