Fisher™ MR98 Series Backpressure Regulators, Relief, and Differential Relief Valves. MR98 Series is used for backpressure or relief applications in liquid, gas, air, and steam service. The Types MR98L, MR98H, and MR98HH are direct-operated and spring-loaded. The Types MR98LD, MR98HD, and MR98HHD use additional pressure loading to maintain relief differential pressures, backpressures or for remote setpoint adjustment.

Features

● Versatility

● Differential Pressure Capability

● Special Service Capabilities

● Large Turndown Ratio

● Graphite Gaskets

● Set Pressures to 400 psig / 27.6 bar

● Tight Shutoff with Elastomer Seats

● Easy Maintenance

● Arctic and Cryogenic Temperature Constructions Options

Specifications

Available Backpressure Constructions:

MR98L: 2 to 38 psig / 0.14 to 2.6 bar set pressure range
MR98H: 15 to 200 psig / 1.0 to 13.8 bar set pressure range
MR98HH: 150 to 375 psig / 10.3 to 25.9 bar set pressure range

Available Pressure Differential Constructions:

MR98LD: 2 to 38 psi / 0.14 to 2.6 bar set pressure range; max differential 150 psi / 10.3 bar
MR98HD: 15 to 200 psi / 1.0 to 13.8 bar set pressure range; max differential 300 psi / 20.7 bar

Available High Pressure Differential Constructions:

MR98HDP: 15 to 200 psi / 1.0 to 13.8 bar set pressure range; max differential 600 psi / 41.4 bar
MR98HHD: 150 to 375 psi / 10.3 to 25.9 bar set pressure range; max differential 400 psi / 27.6 bar

Body and Spring Case Materials:

Gray Cast Iron 
WCC Steel
LCC Steel 
Stainless Steel
Special Alloys: Monel®, Hastelloy® C, Aluminum-Bronze
Contact Sales Office for Special Alloys 

Body Size and End Connection Styles:

1/4-inch
1/2-inch / DN 15
3/4 and 1-inch / DN 20 and 25
1-1/2 and 2-inch / DN 40 and 50 (not available for Types MR95L and MR95LD)

End Connection Styles:

NPT, SWE, and Welded and Integral CL150 RF, CL300 RF, CL600 RF, and PN 16/25/40 RF; all with 14-inch face-to-face (EN flanged-356 mm face-to-face)

MR98H Series Approximate Weights:

1/4 NPT body: 5 lb / 2.3 kg
1/2-in / DN 15 body: 10 lb / 4.5 kg
3/4 and 1-in / DN 20 and 25 bodies: 22 lb / 10 kg
1-1/2 and 2-in bodies / DN 40 and 50: 55 lb / 25 kg

MR98L Series Approximate Weights:

1/4 NPT body: 7 lb / 3.2 kg
1/2-in / DN 15 body: 15 lb / 6.8 kg
3/4 and 1-in / DN 20 and 25 bodies: 35 lb / 16 kg

Maximum Inlet Pressure: 600 psig / 41.4 bar

Maximum Outlet Pressure: 400 psig / 27.6 bar

Pressure Registration: Internal or External

Fisher™ MR98 series backpressure regulators, relief, and differential relief valves