Product Overview | Relief Valve
Outlet pressure is adjusted by loosening locknut and turning spring adjusting screw on top of regulator, then tightening locknut.
7177A Relief Valves are used with or in place of 7142A and 7152A Oil Pressure Regulators.
Relief Valves avoid build-up of pressure upstream of regulators or other equipment, which can occur particularly when burners are turned down to low flows.
More trim options are available upon request to Fives North American Combustion, Inc.
— 7177A Relief Valves have a 25-75 psig spring or 70-140 psig. Other spring ranges are available upon request
Relief valve selection usually is not critical since gph capacities exceed those of pumps encountered in normal piping systems.
— Body: cast iron with stainless trim.
When sizing a relief valve, for every application, the max pressure conditions, the wide-open regulator flow, capacity, and constant downstream demand should be determined. This is then used to select the appropriate relief valve for the application.
— Diaphragm: neoprene.
— Seat: nitrile.
Relief valves can be installed in any position.
— Maximum temperature: 180°F.
CAPACITIES (0.85 sp gr oil @ 48 SSU)
Relief pressure setting (psig)
Pressure Build-up over Relief setting (psig)
5
7
10
15
20
30
50
75
100
Size (inches)
GPM GPM
GPM GPM GPM GPM GPM GPM GPM
Designation
5.2 5.1 5.6
5.4 6.4
7.8 8.4 9.2
9.0 9.9
10.2 11.9 13.0 26.0 29.3 32.5 51.0 56.4 62.9
10.8 11.9 14.0 29.3 31.5 35.8 55.3 59.7 67.2
13.0 14.1 16.3
15.2 16.3 17.4
16.3 17.4 18.4
35 50 75 35 50 75 35 50 75
7177A-03
1/4
7.1
10.8 22.8
13.0 13.0 14.1 26.0 29.3 31.5
15.2 16.3 18.4 30.4 34.7 38.0
19.5
34.7 39.0 43.4
1/2
20.6 24.9 23.9 28.2 38.0 44.5 42.3 48.8
38.0
41.2 45.6 44.5 48.8
7177A-01
41.2
3/4 and 1
7177A-0 7177A-1
62.9 70.5
78.1
68.3 74.8 82.4
47.7
55.3
74.8
81.3 87.9
Note : In 7177A Relief Valves initial flow or bubble point occurs at 5 psig below relief setting. Tight shutoff point occurs at 8 psig below relief setting. LIGHT OIL PIPING SCHEMATIC
To other burner zones
P
Return
P
Recirculating system 7177A Relief Valve
To order, specify: 7177A-(code)-(specify end of spring range) Relief Valve Examples: 7177A-03-75 ¼ " relief valve with 25-75 psi spring 7177A-01-140 ½ " relief valve with 70-140 psi spring
Bulletin 7177A Page 2
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