Emerson MR98 Series User manual

Installation Guide
D103588X014 MR98 Series
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 O󰀩ce or view a copy at www.fisher.com. For
further information refer to MR98 Series Backpressure
Regulators, Relief and Di󰀨erential 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.
Specications
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: Di󰀨erential pressure relief valve
for di󰀨erential 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
Available Constructions (continued)
Type MR98HD: Di󰀨erential pressure relief valve
for di󰀨erential 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: Di󰀨erential pressure relief valve
for di󰀨erential 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: Di󰀨erential pressure relief valve
for di󰀨erential 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 Orice Sizes
1/4 NPT body: 7.22 mm / 0.284 in. orice
DN 15 / 1/2 in. body:
10.56 mm / 0.416 in. orice
DN 20 and 25 / 3/4 and 1 in. bodies:
16.02 mm / 0.631 in. orice
DN 40 and 50 / 1-1/2 and 2 in. bodies:
29 mm / 1.142 in. orice
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 anges (for welded end
connections) and are EN anged 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
1. The pressure/temperature limits in this Installation Guide and any applicable standard or code limitation should not be exceeded.
TYPE PRODUCT SIZE BODY MATERIAL CATEGORY
All 1/4 NPT, DN 15 to
25 / 1/2 to 1 in.
All available
materials SEP
MR98H/MR98HD/
MR98HDP
DN 40 and 50 /
1-1/2 and 2 in.
Steel and
Stainless Steel II

MR98 Series
2
Pressure Registration
Internal or External
Shuto󰀨 Classication Per ANSI/FCI 70-3-2004
Metal Seats: Class IV
PTFE: Class IV
Elastomer Seats: Class VI or better
Specications (continued)
Temperature Capabilities of Body Materials(1)(2)(4)
BODY MATERIAL TEMPERATURE RANGE
Gray Cast Iron -29 to 208°C / -20 to 406°F
WCC Steel(4) -29 to 232°C / -20 to 450°F
LCC Steel(4) -40 to 232°C / -40 to 450°F
Stainless Steel(4), Monel®
or Hastelloy® C -40 to 232°C / -40 to 450°F
Temperature Capabilities of Trim Materials(1)(2)
TRIM MATERIAL
PART TEMPERATURE RANGE
Seat
Diaphragm
O-ring
Diaphragm
Protector
°C °F
Nitrile (NBR) ü ü -40 to 82 -40 to 180
Neoprene (CR) ü-40 to 82 -40 to 180
Fluorocarbon (FKM)(3) ü ü ü -18 to 149(5) 0 to 300(5)
Ethylenepropylene (EPDM) ü ü ü -7 to 135 20 to 275
Sanitary Ethylenepropylene
(EPDM)(1) ü ü ü -7 to 135 20 to 275
Peruoroelastomer (FFKM) ü ü -18 to 218 0 to 425
Polytetrauoroethylene
(PTFE) ü-40 to 204 -40 to 400
Metal ü ü -40 to 450 -40 to 232
1. Sanitary EPDM elastomers meet FDA, USP Class VI and ADI Free requirements.
Flow Coe󰀩cients
BODY SIZE
CVCgC1
DN In.
- - - - 1/4 NPT 1.4 48 34.3
15 1/2 3.4 120 35.3
20 and 25 3/4 and 1 6.5 250 38.5
40 and 50 1-1/2 and 2 20.0 780 39.0
IEC Sizing Coe󰀩cients
BODY SIZE
XTFdFLKm
DN In.
- - - - 1/4 NPT 0.743 0.74 0.95 0.90
15 1/2 0.787 0.78 0.94 0.88
20 and 25 3/4 and 1 0.935 0.70 0.91 0.83
40 and 50 1-1/2 and 2 0.961 0.69 0.94 0.88
Table 1. MR98 Series Body Sizes and Pressure Ranges
TYPE BODY SIZE CONTROL PRESSURE RANGE(1)
DN In. bar psig
MR98L and MR98LD 15, 20 and 25 1/4 NPT, 1/2, 3/4 and 1
0.14 to 0.48 2 to 7
0.41 to 0.97 6 to 14
0.83 to 1.7 12 to 25
1.4 to 2.6 20 to 38
MR98H, MR98HD and
MRR98HDP
15, 20 and 25 1/4 NPT, 1/2, 3/4 and 1
1.0 to 2.4 15 to 35
1.7 to 5.2 25 to 75
4.8 to 9.7 70 to 140
9.0 to 13.8 130 to 200
40 and 50 1-1/2 and 2
0.34 to 2.4 5 to 35
1.4 to 4.5 20 to 65
3.4 to 6.9 50 to 100
5.2 to 11.7 75 to 170
MR98HH and MR98HHD 15, 20 and 25 1/4 NPT, 1/2, 3/4 and 1 10.3 to 25.9 150 to 375
1. All springs may be backed o󰀨 to 0 bar / 0 psig. However, highest capacities and best performances are obtained by using these springs in their recommended ranges.
Monel® is a mark owned by Special Metals Corporation.
Hastelloy® C is a mark owned by Haynes International, Inc.
1. The pressure/temperature limits in this Installation Guide and any applicable standard or code limitation should not be exceeded.
2. Pressure and/or the body end connection may decrease these maximum temperatures.
3. Not for use on steam service.
4. Meets API 614 Requirements (with Stainless steel trim).
5. Limited to 93°C / 200°F for hot water.

MR98 Series
3
Installation
▲ WARNING
Only qualied personnel shall install or
service a relief valve or backpressure
regulator. Relief valve or backpressure
regulator should be installed, operated
and maintained in accordance with
international and applicable codes
and regulations and Emerson Process
Management Regulator Technologies,
Inc. instructions.
If using a relief valve or backpressure
regulator on a hazardous or ammable
uid service, personal injury and
property damage could occur due to re
or explosion of vented uid that may
have accumulated. To prevent such
injury or damage, provide piping or
tubing to vent the uid to a safe, well-
ventilated area or containment vessel.
Also, when venting a hazardous uid,
the piping or tubing should be located
far enough away from any buildings
or windows so to not create a further
hazard and the vent opening should be
protected against anything that could
clog it.
Personal injury, equipment damage
or leakage due to escaping uid
or bursting of pressure-containing
parts may result if this relief valve or
backpressure regulator is overpressured
or is installed where service conditions
could exceed the limits given in
the Specications section or where
conditions exceed any ratings of the
adjacent piping or piping connections.
To avoid such injury or damage, provide
pressure-relieving or pressure-limiting
devices (as required by the appropriate
code, regulation or standard) to prevent
service conditions from exceeding limits.
Additionally, physical damage to the
relief valve or backpressure regulator
could result in personal injury and
property damage due to escaping uid.
To avoid such injury and damage,
install the relief valve or backpressure
regulator in a safe location.
Clean out all pipelines before installation of the relief
valve or backpressure regulator and check to be sure
the relief valve or backpressure regulator has not been
damaged or has collected foreign material during
shipping. For NPT bodies, apply pipe compound to
the external pipe threads. For anged bodies, use
suitable line gaskets and approved piping and bolting
practices. Install the relief valve or backpressure
regulator in any position desired, unless otherwise
specied, but be sure ow through the body is in the
direction indicated by the arrow on the body.
Table 2. Maximum Cold Working Pressures of Body Size and Materials(1)(2)
REGULATOR
TYPE
BODY SIZE BODY AND SPRING CASE MATERIAL
MAXIMUM
INLET PRESSURE(3)
MAXIMUM OUTLET
PRESSURE
MAXIMUM SPRING
CASE PRESSURE
DN In. bar psig bar psig bar psig
MR98L/
MR98LD
- - - -
15, 20, 25
1/4
1/2, 3/4, 1
Gray Cast Iron 4.1 60 4.1 60 3.4 50
Steel(4); Stainless Steel(4); Monel®(5);
Hastelloy® C(5) 10.3 150 10.3 150 8.6 125
MR98H/
MR98HD
- - - -
15, 20, 25,
40, 50
1/4,
1/2, 3/4, 1,
1-1/2, 2
Gray Cast Iron 20.7 300 20.7 300 17.2 250
Steel(4); Stainless Steel(4); Monel®(5);
Hastelloy® C(5); Aluminum-Bronze(5) 20.7 300 20.7 300 20.7 300
MR98HDP(6)
- - - -
15, 20, 25,
40, 50
1/4,
1/2, 3/4, 1,
1-1/2, 2
Steel(4) 41.4 600 41.4 600 41.4 600
Stainless Steel(4); Monel®(5); Hastelloy® C(5);
Aluminum-Bronze(5) 37.9 550 37.9 550 37.9 550
MR98HH/
MR98HHD(6)
- - - -
15, 20, 25
1/4,
1/2, 3/4, 1
Steel(4); Stainless Steel(4); Monel®(5);
Hastelloy® C(5); Aluminum-Bronze(5) 27.6 400 27.6 400 27.6 400
1. The pressure/temperature limits in this Installation Guide and any applicable standard limitation should not be exceeded.
2. Temperature, trim material and/or the body end connection may decrease these maximum pressures.
3. Maximum inlet pressure equals set pressure plus build-up.
4. Steel and stainless steel body and spring case constructions meet API 614 requirments with SST trim.
5. Not available for 1/4 NPT body size.
6. Maximum di󰀨erential pressure between inlet pressure and loading pressure should never exceed 20.7 bar / 300 psig.
Monel® is a mark owned by Special Metals Corporation.
Hastelloy® C is a mark owned by Haynes International, Inc.

MR98 Series
4
Note
It is important that the relief valve or
backpressure regulator be installed
so that the vent hole in the spring
case is unobstructed at all times. For
outdoor installations, the relief valve
or backpressure regulator should be
located away from vehicular tra󰀩c and
positioned so that water, ice and other
foreign materials cannot enter the spring
case through the vent. Avoid placing the
relief valve or backpressure regulator
beneath eaves or downspouts and be
sure it is above the probable snow level.
Overpressure Protection
Maximum inlet pressure depend upon body materials
and temperatures. See Specications section or the
maximum inlet pressure of the valve and the maximum
spring case loading pressures stamped on the
nameplate of Types MR98LD, MR98HD, MR98HDP
and MR98HHD. The valve should be inspected for
damage after any overpressure condition. Fisher™
relief valve or backpressure regulators are NOT
ASME safety relief valves.
Startup
The relief valve or backpressure regulator is factory
set at approximately the midpoint of the spring range
or the pressure requested, so an initial adjustment
may be required to give the desired results. With
proper installation completed and relief valves properly
adjusted, slowly open the upstream and downstream
shuto󰀨 valves (if applicable).
Adjustment
To change the control pressure, remove closing
cap or loosen the jam nut and turn the adjusting
screw clockwise to increase control pressure or
counterclockwise to decrease pressure. Monitor
the control pressure with a test gauge during the
adjustment. Replace closing cap or tighten the jam nut
to maintain the desired setting.
Taking Out of Service (Shutdown)
▲ WARNING
To avoid personal injury resulting
from sudden release of pressure,
isolate the relief valve or backpressure
regulator from all pressure before
attempting disassembly.
Parts List
Key Description
1 Body
2 Spring Case
3* Orice
4* Valve Plug
5 Bottom Plug
7 Valve Plug Guide
8 Lower Spring Seat
9 Upper Spring Seat
10 Pusher Post
11 Control Spring
12* Diaphragm (2 required for metal, FKM and EPDM diaphragms)
13 Nameplate
14 Diaphragm Protector (not shown)
15 Adjusting Screw
16 Cap Screws
Types MR98L and MR98LD
1/4 NPT; DN 15 / 1/2 in. bodies - 10 required
DN 20 and 25 / 3/4 and 1 in. bodies - 12 required
Types MR98H, MR98HD, MR98HH, MR98HDP and MR98HHD
1/4 NPT body - 6 required
DN 15 to 50 / 1/2 to 2 in. bodies - 8 required
17 Jam Nut
18 Drive Screw (4 required)
19* Diaphragm Gasket (2 required for pressure loaded spring case)
21 Diaphragm Head
22 Adjusting Screw Assembly
23 Handwheel (not shown)
24 Machine Screw
25 O-ring Retainer
25 Seat Retainer
28 Lockwasher
29* Gasket
31 Locknut
32 Stu󰀩ng Box
*Recommended Spare Part
33 Adjusting Screw
34 Packing Follower
35 Stu󰀩ng Box Nut
36 Packing V-Ring (3 required)
37* Stu󰀨 Box Gasket
38 Handwheel / Handle
39 Internal Adaptor
40 External Adaptor
41 Machine Screw
41 Jam Nut
42 Spring
43 Washer
44 Washer
45* O-ring
47 NACE Tag (not shown)
48 Tag Wire (not shown)
49 Lockwasher (not shown)
50* Sealing Washer
51 Vent (not shown)
52 Plug
53* Valve Plug O-ring
57 Jam Nut (not shown)
58 Washer
59* O-ring
59* L-ring
62 Adaptor (not shown)
63* Bottom Plug Seal
64 Flow Arrow
65 Pipe Plug (not shown)
66 Pressure Gauge (not shown)
68 Restriction (not shown)
69 ATEX Tag (not shown)
70 PED Tag (not shown)
Key Description

2
17
11
50
28
8
58
4
31
21
12
29
1
13 18
64 18
L2
7
L2
5
L2
22
L2
24 T
3L2
9L2
63
L1
L4
59
25
52 53
10
L2
16
L2(2)
19
15
GF04917
MR98 Series
5
APPLY(1):
T = THREAD LOCKER
L1 = GENERAL PURPOSE PTFE OR LITHIUM GREASE FOR O-RINGS
L2 = ANTI-SEIZE COMPOUND
L4 = GRAPHITE SEALANT FOR GRAPHITE RING
1. Lubricants and sealants must be selected such that they meet the temperature requirements.
2. Apply L2 (anti-seize compound) on key 16 for Stainless Steel bolts.
3. Apply L4 (graphite sealant) instead of L1 (general purpose PTFE or lithium grease) on key 63 for graphite ring.
Figure 1. Type MR98L Assembly
METAL DIAPHRAGM OPTION SEALED ADJUSTING
SCREW OPTION
TEE-HANDLE
OPTION
COMPOSITE SEAT
OPTION CONTROL LINE
OPTION
OR(3)

GF04920
44 41
25
59
52
29
29
19
19
12
53
38
35
40
43
11 10
8
12
1
29
34
39
42
32
2
31
28
16
45
58
4
7
L2
33
L2
37 L1
24 T
36 L3
9
L2
3L2
5L2
L1
63
L1
L4
L2(2)
L2
Americas
McKinney, Texas 75070 USA
T [phone]
[phone]
Europe
Bologna 40013, Italy
T [phone]
Asia Pacic
Singapore 128461, Singapore
T [phone]
Middle East and Africa
Dubai, United Arab Emirates
T [phone]
Emerson Automation Solutions
Regulator Technologies
Facebook.com/EmersonAutomationSolutions
LinkedIn.com/company/emerson-automation-solutions
Twitter.com/emr_automation
[email protected]
For further information on the current
PED revision see Bulletin: D103053X012
or scan the QR code.
The distinctive diamond shape cast into every spring
case uniquely identifies the regulator as part of the
Fisher™ brand and assures you of the highest-quality
engineering, durability, performance, and support.
Fisher.com
MR98 Series
D103588X014 © 2014, 2022 Emerson Process Management Regulator
Technologies, Inc. All rights reserved. 10/22.
The Emerson logo is a trademark and service mark of Emerson
Electric Co. All other marks are the property of their prospective owners.
Fisher™ is a mark owned by Fisher Controls International LLC, a
business of Emerson Automation Solutions.
The contents of this publication are presented for informational purposes
only, and while every e󰀨ort has been made to ensure their accuracy,
they are not to be construed as warranties or guarantees, express or
implied, regarding the products or services described herein or their use
or applicability. All sales are governed by our terms and conditions, which
are available upon request. We reserve the right to modify or improve the
designs or specications of such products at any time without notice.
Emerson Process Management Regulator Technologies, Inc does not
assume responsibility for the selection, use or maintenance of any product.
Responsibility for proper selection, use and maintenance of any Emerson
Process Management Regulator Technologies, Inc. product remains solely
with the purchaser.
APPLY(1):
T = THREAD LOCKER
L1 = GENERAL PURPOSE PTFE OR LITHIUM GREASE FOR O-RINGS
L2 = ANTI-SEIZE COMPOUND
L3 = SILICONE GREASE
L4 = GRAPHITE SEALANT FOR GRAPHITE RING
1. Lubricants and sealants must be selected such that they meet the temperature requirements.
2. Apply L2 (anti-seize compound) on key 16 for Stainless Steel bolts.
3. Apply L4 (graphite sealant) instead of L1 (general purpose PTFE or lithium grease) on key 63 for graphite ring.
Figure 2. Type MR98HD Assembly with 1/4 NPT, DN 15 to 25 / 1/2 to 1 In. Bodies
CONTROL LINE OPTION COMPOSITE SEAT OPTION
SEE DETAIL B SEE DETAIL A
METAL DIAPHRAGM OPTION
DETAIL A
OR
(3)
DETAIL B