Water Pressure Safety Relief Valve- Series 174A
¾" to 2" (20 - 50mm)
Bronze body safety relief valves for pressure protection only of all types of hot water heating boiler equipment. Pressure range 30 to 150 psi (2 - 10 bars) with corresponding high ratings from 650,000 to 14,370,000 BTU/hr. Female inlet and outlet connections. Sizes ¾" to 2" (20 to 50mm).
OPERATION
As thermal expansion conditions develop, pressure builds up to the setting of the relief valve. This will cause discharging of small quantity of water
Should operating controls fail, permitting runaway firing, the boiler water may reach steam temperatures. The valve will then open to discharge steam at the rate or faster than the boiler can generate it, thus restoring system pressure to a safer level.
OPERATION
As thermal expansion conditions develop, pressure builds up to the setting of the relief valve. This will cause discharging of small quantity of water
Should operating controls fail, permitting runaway firing, the boiler water may reach steam temperatures. The valve will then open to discharge steam at the rate or faster than the boiler can generate it, thus restoring system pressure to a safer level.
Important: The discharge line must be the same size as the valve outlet, and must pitch downward from the valve to a safe place for disposal. Valve lever must be tripped at least once a year to insure that waterways are clear. This device is designed for emergency safety relief and shall not be used as an operating control.
FEATURES
SPECIFICATIONS
An ASME Section IV certified pressure relief valve shall be installed on each boiler as noted. The valve shall have a BTU rating in excess of the BTU rating of the boilers heating output. Each hot water space heating boiler shall be equipped with a pressure relief valve set to relieve below the maximum boiler working pressure. The valve shall feature a raised seat and non-mechanical disc alignment. Working parts and spring shall be isolated from any discharge by a high temperature resistant material. Valve shall be a Watts 174A Series.
MATERIALS
STANDARDS
ASME
Tested and rated by A.S.M.E. National Board of Boiler and Pressure Vessel Inspectors.
Meets Military Spec. MIL-V-18634B, Type I, Class 3A, Style A (Bronze Body).
CAPACITY
BTU/hr Steam Pressure Discharge Capacities
As tested and rated by the National Board of Boiler and Pressure Vessel Inspectors
PRESSURE-TEMPERATURE
- Seat located above drain; water can’t be trapped and sediment can’t foul seat.
- Non-mechanical seat-to-disc alignment will not stick or freeze.
- Water seal of high temperature resisting material isolates spring working parts from water during relief.
An ASME Section IV certified pressure relief valve shall be installed on each boiler as noted. The valve shall have a BTU rating in excess of the BTU rating of the boilers heating output. Each hot water space heating boiler shall be equipped with a pressure relief valve set to relieve below the maximum boiler working pressure. The valve shall feature a raised seat and non-mechanical disc alignment. Working parts and spring shall be isolated from any discharge by a high temperature resistant material. Valve shall be a Watts 174A Series.
- Bronze body construction
- Nonmetallic disc-to-metal seating
ASMETested and rated by A.S.M.E. National Board of Boiler and Pressure Vessel Inspectors.
Meets Military Spec. MIL-V-18634B, Type I, Class 3A, Style A (Bronze Body).
BTU/hr Steam Pressure Discharge Capacities
As tested and rated by the National Board of Boiler and Pressure Vessel Inspectors
| Set Pressure | ¾" x ¾" 20 x 20mm Model M3 |
1" x 1" 25 x 25mm Model M1 |
1 ¼" x 1 ¼" 32 x 32mm Model M1 |
1 ½" x 1 ½" 40 x 40mm Model M |
2" x 2" 50 x 50mm Model M |
|
|---|---|---|---|---|---|---|
| psi | bars | |||||
| 30 | 2.07 | 650,000 | 1,005,000 | 1,682,000 | 2,020,000 | 3,815,000 |
| 33 | 2.27 | 695,000 | 1,075,000 | 1,799,000 | 2,165,000 | 4,080,000 |
| 35 | 2.41 | 725,000 | 1,125,000 | 1,896,000 | 2,255,000 | 4,250,000 |
| 36 | 2.48 | 740,000 | 1,145,000 | 1,915,000 | 2,305,000 | 4,340,000 |
| 40 | 2.76 | 800,000 | 1,240,000 | 2,070,000 | 2,490,000 | 4,690,000 |
| 45 | 3.10 | 875,000 | 1,355,000 | 2,265,000 | 2,725,000 | 5,130,000 |
| 50 | 3.45 | 950,000 | 1,470,000 | 2,459,000 | 2,950,000 | 5,570,000 |
| 55 | 3.79 | 1,025,000 | 1,590,000 | 2,653,000 | 3,190,000 | 6,010,000 |
| 60 | 4.13 | 1,100,000 | 1,705,000 | 2,847,000 | 3,425,000 | 6,450,000 |
| 65 | 4.58 | 1,170,000 | 1,820,000 | 3,041,000 | 3,655,000 | 6,890,000 |
| 70 | 4.82 | 1,245,000 | 1,935,000 | 3,235,000 | 3,890,000 | 7,330,000 |
| 75 | 5.17 | 1,320,000 | 2,055,000 | 3,429,000 | 4,125,000 | 7,770,000 |
| 80 | 5.51 | 1,400,000 | 2,170,000 | 3,623,000 | 4,360,000 | 8,210,000 |
| 85 | 5.86 | 1,470,000 | 2,285,000 | 3,817,000 | 4,590,000 | 8,650,000 |
| 90 | 6.20 | 1,545,000 | 2,400,000 | 4,011,000 | 4,825,000 | 9,090,000 |
| 95 | 6.55 | 1,620,000 | 2,520,000 | 4,205,000 | 5,060,000 | 9,532,000 |
| 100 | 6.89 | 1,695,000 | 2,635,000 | 4,399,000 | 5,290,000 | 9,970,000 |
| 105 | 7.23 | 1,770,000 | 2,750,000 | 4,593,000 | 5,525,000 | 10,410,000 |
| 110 | 7.58 | 1,845,000 | 2,865,000 | 4,787,000 | 5,760,000 | 10,850,000 |
| 115 | 7.92 | 1,920,000 | 2,980,000 | 4,981,000 | 5,990,000 | 11,290,000 |
| 120 | 8.27 | 1,995,000 | 3,100,000 | 5,175,000 | 6,225,000 | 11,730,000 |
| 125 | 8.61 | 2,070,000 | 3,215,000 | 5,370,000 | 6,460,000 | 12,170,000 |
| 130 | 8.96 | 2,145,000 | 3,330,000 | 5,564,000 | 6,690,000 | 12,610,000 |
| 135 | 9.30 | 2,220,000 | 3,445,000 | 5,758,000 | 6,925,000 | 13,050,000 |
| 140 | 9.65 | 2,295,000 | 3,565,000 | 5,592,000 | 7,160,000 | 13,490,000 |
| 145 | 9.99 | 2,370,000 | 3,680,000 | 6,146,000 | 7,390,000 | 13,930,000 |
| 150 | 10.34 | 2,445,000 | 3,795,000 | 6,340,000 | 7,630,000 | 14,370,000 |
Pressure range: 30 psi to 150 psi (2 to 10 bars) with corresponding high BTU/hr ratings from 650,000 to 14,370,000 BTU/hr.
Maximum Temperature: 250°F (121°C).
DIMENSIONS-WEIGHT
Maximum Temperature: 250°F (121°C).
| Size(DN) | Model | Height | Length | Weight | ||||
|---|---|---|---|---|---|---|---|---|
| in. | mm | in. | mm | in. | mm | lbs. | kg | |
| ¾ x ¾ | 20 x 20mm | M3 | 5 ¹/8 | 130 | 2 ½ | 64 | 1.50 | .7 |
| 1 x 1 | 25 x 25mm | M1 | 5 ¾ | 146 | 3 | 76 | 3.13 | 1.4 |
| 1 ¼ x 1 ¼ | 32 x 32mm | M1 | 8 ³/8 | 213 | 4 ¾ | 121 | 6.25 | 2.8 |
| 1 ½ x 1 ½ | 40 x 40mm | M | 9 | 229 | 4 7/8 | 124 | 7.25 | 3.3 |
| 2 x 2 | 50 x 50mm | M | 11 5/8 | 295 | 6 ¼ | 159 | 13.75 | 6.2 |