MR98 Series Backpressure Regulators, Relief and Differential Relief Valve

Product catalog summary

Introduction
The MR98 Series is designed for backpressure or relief applications across various services such as liquid, gas, air, and steam. It includes direct-operated and spring-loaded types, with options for differential pressure maintenance and remote setpoint adjustments.

Specifications
The series includes models like MR98L, MR98H, MR98HH, MR98LD, MR98HD, MR98HDP, and MR98HHD, each with specific pressure ranges and body sizes. Materials used include gray cast iron, steel, stainless steel, aluminum-bronze, Hastelloy® C, and Monel® for fluid compatibility and corrosion resistance.

Body Sizes and End Connection Styles
Body sizes range from 1/4 NPT to 2 inches, with end connection styles such as NPT, SWE, and welded options. Construction materials comply with NACE standards.

Flow Coefficients and Capacities
Flow coefficients and capacities are detailed in tables, providing IEC sizing coefficients and regulating Cv values for different types and sizes.

Features
The MR98 Series offers versatility, excellent fluid compatibility, stable regulation, compact design, differential pressure capability, and options for sour gas service and arctic temperature constructions. It complies with API 614 standards.

Principle of Operation
Valves respond to upstream pressure changes, with pressure changes registering under the diaphragm to maintain desired pressure levels.

Operational Mechanism
Controlled by a diaphragm and spring mechanism, the valve opens to vent excess pressure when it exceeds the spring setting and closes when pressure drops below the setpoint.

Capacity Information
Relieving capacities are provided in SCFH for air and gallons per minute for water, with conversion factors for other gases and specific gravity adjustments for accurate calculations.

Sizing and Installation
Guidelines for determining flow rates and installation emphasize correct flow direction, referencing an instruction manual for detailed procedures.

Compliance and Materials
Valves comply with NACE standards for sour gas applications. A table lists trim materials, including elastomer and metal seats, diaphragms, and other components.

Tables and Figures
Includes tables detailing trim materials, construction materials, maximum pressures, temperature capabilities, and water relief capacities, along with figures illustrating operational schematics and valve configurations.

Dimensions and Ordering Information
Provides dimensions for various MR98 regulators and an ordering guide for selecting regulator type, body size, material, end connection style, and more. Includes information on replacement parts kits and quick order guides.

Key Features
MR98 Series regulators are identified by a distinctive diamond shape on the spring case, ensuring high-quality engineering, durability, and performance. Emphasizes proper selection, use, and maintenance.

Contact Information
Contact details for Emerson Automation Solutions in various regions are provided for further inquiries and support.

Catalog excerpts

MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-1

MR98 Series Backpressure Regulators, Relief and Differential Relief Valves Figure 1. Typical MR98 Series Backpressure Regulators, Relief and Differential Relief Valves

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-2

MR98 Series Specifications 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: Backpressure regulator / relief valve for spring settings range from 2 to 38 psig / 0.14 to 2.6 bar. 1/4 in. to 1 in. body sizes only. Type MR98H: Backpressure regulator / relief valve for spring settings range from 5 to 200 psig / 0.34 to 13.8...

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-3

MR98 Series Specifications (continued) Shutoff Classification Per ANSI/FCI 70-3-2004 Metal Seats: Class IV Polytetrafluoroethylene (PTFE): Class IV Elastomer Seats: Class VI or better Pressure Registration Internal or External Approximate Weights MR98H Series: 1/4 NPT body: 5 lbs / 2.3 kg 1/2 in. / DN 15 body: 10 lbs / 4.5 kg 3/4 and 1 in. / DN 20 and 25 bodies: 22 lbs / 10 kg 1-1/2 and 2 in. / DN 40 and 50 bodies: 55 lbs / 25 kg Introduction MR98 Series (Figure 1) is used for backpressure or relief applications in liquid, gas, air and steam service. The Types MR98L, MR98H and MR98HH are directoperated...

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-4

MR98 Series Table 1. Types MR98L and MR98LD Regulators Body Constructions Without Control Line and Gauge Port Without Control Line and Gauge Port Welded CL150 RF Welded CL300 RF Welded PN 16/25/40 RF With Control Line but Without Gauge Port Without Control Line and Gauge Port Welded PN 16/25/40 RF With Control Line but Without Gauge Port With Gauge Port but Without Control Line Welded CL150 RF Welded CL300 RF Welded PN 16/25/40 RF NPT SWE Without Control Line and Gauge Port Welded PN 16/25/40 RF With Control Line but Without Gauge Port With Gauge Port but Without Control Line Welded CL150 RF...

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-5

MR98 Series Table 2. Types MR98H, MR98HD, MR98HDP, MR98HH and MR98HHD Regulators Body Constructions Without Control Line and Gauge Port BODY CONSTRUCTION BODY SIZE BODY MATERIAL Without Control Line and Gauge Port 1/2 in. / DN 15 Welded CL300 RF Welded PN 16/25/40 RF Integral CL150 RF Integral CL300 RF Integral PN 16/25/40 RF NPT With Control Line but Without Gauge Port Without Control Line and Gauge Port Welded CL150 RF Welded CL300 RF Welded PN 16/25/40 RF NPT With Control Line but Without Gauge Port With Gauge Port but Without Control Line Welded CL150 RF Welded CL300 RF Welded PN 16/25/40...

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-6

MR98 Series Table 2. Types MR98H, MR98HD, MR98HDP, MR98HH and MR98HHD Regulators Body Constructions (continued) NPT SWE Without Control Line and Gauge Port Welded CL150 RF Welded CL300 RF Welded PN 16/25/40 RF NPT With Control Line but Without Gauge Port With Gauge Port but Without Control Line Welded CL150 RF Welded CL300 RF Welded PN 16/25/40 RF NPT SWE Welded CL150 RF Without Control Line and Gauge Port Welded CL300 RF Welded PN 16/25/40 RF Integral CL150 RF Integral CL300 RF NPT With Control Line but Without Gauge Port With Gauge Port but Without Control Line Welded CL150 RF Welded CL300...

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-7

MR98 Series Table 3. MR98 Series Body Sizes, Pressure Ranges and Spring Information TYPE SPRING WIRE DIAMETER SPRING FREE LENGTH SPRING MATERIAL SPRING PART NUMBER SPRING COLOR Zinc-plated steel Zinc-plated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated Stainless steel Stainless steel Stainless steel Zinc-plated steel Zinc-plated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated steel Powder-coated...

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-8

MR98 Series ADJUSTING SCREW CONTROL SPRING DIAPHRAGM VALVE PLUG TYPE MR98H WITH INTERNAL PRESSURE REGISTRATION 1/2 IN. / DN 15 TYPE MR98H WITH EXTERNAL PRESSURE REGISTRATION INLET PRESSURE INLET PRESSURE OUTLET PRESSURE OUTLET PRESSURE ATMOSPHERIC PRESSURE ATMOSPHERIC PRESSURE SIDE AND INTERNAL VIEW OF 3/4 TO 2 IN. / DN 20 TO 50 TYPE MR98H WITH EXTERNAL PRESSURE REGISTRATION (ALSO TYPICAL OF TYPE MR98L, 1/2 TO 2 IN. / DN 15 TO 50 BODIES) TYPE T208 WITH INTERNAL REGISTRATION METAL DIAPHRAGMS METAL DIAPHRAGM FOR TYPE MR98H WITH TWO METAL DIAPHRAGMS (ALSO TYPICAL OF TYPES MR98HH AND MR98L EXCEPT...

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-9

CONTROL SPRING LOADING PRESSURE INLET TAP DIAPHRAGM VALVE PLUG ORIFICE CONTROL LINE TAP INLET PRESSURE INLET PRESSURE OUTLET PRESSURE OUTLET PRESSURE LOADING PRESSURE LOADING PRESSURE TYPES MR98HD AND MR98HDP WITH INTERNAL PRESSURE REGISTRATION TYPES MR98HD AND MR98HDP WITH EXTERNAL PRESSURE REGISTRATION METAL DIAPHRAGMS FOR TYPES MR98HD, MR98HDP, MR98HHD AND MR98LD WITH METAL DIAPHRAGMS, ASSEMBLE DIAPHRAGM GASKETS UNDER AND ABOVE THE METAL DIAPHRAGMS AS SHOWN ABOVE Figure 2. MR98 Series Operational Schematics (continued) Differential relief valves are used to maintain a differential pressure...

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-10

MR98 Series the table capacities by the following appropriate conversion factors: 1.29 for 0.6 specific gravity natural gas, 0.808 for propane, 0.707 for butane or 1.018 for nitrogen. For gases of other specific gravities, divide by the square root of the appropriate specific gravity. Then, if capacity is desired in normal cubic meters per hour (Nm3/h) at 0°C and 1.01325 bar, multiply SFCH by 0.0268. Typical relieving capacities in lbs per hour and kilogram per hour of saturated steam are shown in Tables 16, 21 and 26. Tables 14, 15, 19, 20, 24 and 25 give relieving capacities in U.S. gallons...

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MR98 Series Backpressure Regulators, Relief and Differential Relief Valve-11

ORIFICE/ VALVE PLUG 416 Stainless Steel 316 Stainless Steel Alloy 6(1) Hastelloy® C Monel® 416 Stainless Steel 316 Stainless Steel 416 Stainless Steel 316 Stainless Steel 416 Stainless Steel 316 Stainless Steel SEAT 416 Stainless Steel 316 Stainless Steel Alloy 6(1) Hastelloy® C Monel® Nitrile (NBR) Nitrile (NBR) Fluorocarbon (FKM) Fluorocarbon (FKM) Ethylenepropylene (EPDM) Ethylenepropylene (EPDM) VALVE PLUG STEM/STEM GUIDE GUIDE 416 Stainless Steel 416 Stainless Steel 316 Stainless Steel 316 Stainless Steel 316 Stainless Steel 316 Stainless Steel Hastelloy® C Hastelloy® C ® Monel Monel® 416...

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