This section lists the specifications for the MR98 Series regulators. Factory specification such as type, maximum inlet pressure, maximum temperature, maximum outlet pressure, spring range, orifice size, and seat material are stamped on the nameplate fastened on the regulator at the factory.
Available Constructions
Type MR98L: Direct-operated low pressure
backpressure regulator/relief valve with 2 to
38 psig / 0.14 to 2.6 bar set pressure range
Type MR98H: Direct-operated high pressure
backpressure regulator/relief valve with 5 to
200 psig / 0.34 to 13.8 bar set pressure range
Type MR98HH: Direct-operated high pressure
backpressure/relief valve with 150 to 375 psig /
10.3 to 25.9 bar set pressure range
Type MR98LD: Pressure-loaded low pressure
differential pressure relief valve with 2 to 38 psi /
0.14 to 2.6 bar set pressure range
Type MR98HD: Pressure-loaded high pressure
differential pressure relief valve with 5 to 200 psi /
0.34 to 13.8 bar set pressure range
Type MR98HHD: Pressure-operated high
pressure backpressure/relief valve with 150
to 375 psi / 10.3 to 25.9 bar differential set
pressure range
Body and Orifice Sizes
1/4 NPT: 0.284 inch / 7.22 mm
1/2-inch / DN 15: 0.416 inch / 10.56 mm
3/4 and 1-inch / DN 20 and 25:
0.631 inch / 16.02 mm
1-1/2 and 2-inch / DN 40 and 50:
1.142 inches / 29 mm
Maximum Spring Case Loading Pressure for
Types MR98LD, MR98HD, and MR98HHD
(Spring Setting Plus Loading Pressure)(1)(2)
Type MR98LD Spring Case
Gray Cast Iron: 50 psig / 3.4 bar
Steel or Stainless steel: 125 psig / 8.6 bar
Type MR98HD Spring Case
Gray Cast Iron: 250 psig / 17.2 bar
Steel or Stainless steel: 300 psig / 20.7 bar
Type MR98HHD Spring Case
Steel or Stainless steel: 300 psig / 20.7 bar
