Emerson FISHER MR98 Series Installation Manual

Installation Guide

D103588X014

English – October 2022

Introduction

This Installation Guide provides instructions for

installation, startup and adjustment. To receive a

copy of the instruction manual, contact your local

Sales Office or view a copy at www.fisher.com. For

further information refer to MR98 Series Backpressure

Regulators, Relief and Differential Relief valves

Instruction Manual, D103588X012.

P.E.D. Category

This product may be used as a safety accessory

with pressure equipment in the following Pressure

Equipment Directive. It may also be used outside

of the Pressure Equipment Directive using Sound

Engineering Practice (SEP) per table below. For

information on the current PED revision see Bulletin:

D103053X012. For information on the current PED

revision see Bulletin: D103053X012.

TYPE

PRODUCT SIZE

1/4 NPT, DN 15 to

All

25 / 1/2 to 1 in.

MR98H/MR98HD/

DN 40 and 50 /

MR98HDP

1-1/2 and 2 in.

Specifications

Available Constructions

Type MR98L: Backpressure regulator/relief valve

for spring settings range from 0.14 to 2.6 bar /

2 to 38 psig, available for 1/4 NPT to DN 25 / 1 in.

body sizes only

Type MR98H: Backpressure regulator/relief valve

for spring settings range from 0.34 to 13.8 bar /

5 to 200 psig

Type MR98HH: Backpressure regulator/relief

valve for spring settings range from 10.3 to

25.9 bar / 150 to 375 psig

Type MR98LD: Differential pressure relief valve

for differential set pressures range from 0.14 to

2.6 bar / 2 to 38 psi with maximum inlet/outlet

pressure up to 10.3 bar / 150 psi, available for

1/4 NPT to DN 25 /1 in. body sizes only

1. The pressure/temperature limits in this Installation Guide and any applicable standard or code limitation should not be exceeded.

BODY MATERIAL

CATEGORY

All available

SEP

materials

Steel and

II

Stainless Steel

Available Constructions (continued)

Type MR98HD: Differential pressure relief valve

for differential set pressures from 0.34 to

13.8 bar / 5 to 200 psi with maximum inlet/outlet

pressure up to 20.7 bar / 300 psi

Type MR98HDP: Differential pressure relief valve

for differential set pressures range from 0.34 to

13.8 bar / 5 to 200 psi with maximum inlet/outlet

pressure up to 41.4 bar / 600 psi

Type MR98HHD: Differential pressure relief valve

for differential set pressures range from 10.3 to

25.9 bar / 150 to 375 psi with maximum inlet/outlet

pressure up to 27.6 bar / 400 psi

Body and Orifice Sizes

1/4 NPT body: 7.22 mm / 0.284 in. orifice

DN 15 / 1/2 in. body:

10.56 mm / 0.416 in. orifice

DN 20 and 25 / 3/4 and 1 in. bodies:

16.02 mm / 0.631 in. orifice

DN 40 and 50 / 1-1/2 and 2 in. bodies:

29 mm / 1.142 in. orifice

End Connection Styles

NPT, SWE and Welded and Integral CL150 RF,

CL300 RF and PN 16/25/40 RF; all sizes are

fabricated with slip-on flanges (for welded end

connections) and are EN flanged 356 mm /

14 in. face-to-face

Set Pressure Ranges

(1)

See Table 1

Maximum Cold Working Pressures of Body Size

and Materials

(1)

See Table 2

Maximum Inlet, Outlet and Spring Case

Pressure Ratings

(1)

See Table 2

MR98 Series