CAPACITIES

(0.85 sp gr oil @ 48 SSU)

Note

:  In 7177A Relief Valves initial fl ow 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 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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Recirculating system

7177A Relief Valve

P

P

 

5 7 10 

15 

20 

30 

50 

75 

100

 

GPM GPM  GPM GPM GPM GPM GPM GPM GPM

 5.2 

5.4 

7.8  9.0 

10.2  10.8  13.0  15.2  16.3

 5.1 

6.4 

8.4  9.9 

11.9  11.9  14.1  16.3  17.4

 5.6 

7.1 

9.2  10.8  13.0  14.0  16.3  17.4  18.4

 13.0 

15.2 

19.5  22.8  26.0  29.3  34.7  39.0  43.4

 13.0 

16.3 

20.6  24.9  29.3 

31.5  38.0  41.2  45.6

 14.1 

18.4 

23.9  28.2  32.5  35.8  41.2  44.5  48.8

 26.0 

30.4 

38.0  44.5 

51.0 

55.3  62.9  70.5  78.1

 29.3 

34.7 

42.3  48.8  56.4 

59.7  68.3  74.8  82.4

 31.5 

38.0 

47.7  55.3  62.9  67.2  74.8  81.3  87.9

Designation

7177A-03

1/4

1/2

3/4

and 1

7177A-0

7177A-1

7177A-01

Pressure Build-up over Relief setting (psig)

Size

(inches)

Relief

pressure

setting

(psig)

35
50
75
35
50
75

35
50
75

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 fl ows.

Relief valve selection usually is not critical since gph capacities 
exceed those of pumps encountered in normal piping systems.

When sizing a relief valve, for every application, the max 
pressure conditions, the wide-open regulator fl ow, capacity, and 
constant downstream demand should be determined. This is then 
used to select the appropriate relief valve for the application.

Relief valves can be installed in any position.

Outlet pressure is adjusted by loosening locknut and turning 
spring adjusting screw on top of regulator, then tightening 
locknut.

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

—

  Body: cast iron with stainless trim.

—

  

Diaphragm: neoprene.

—

 

Seat: nitrile.

—

  

Maximum temperature: 180°F.

Product Overview | Relief Valve