Emerson LR125 Data Sheet

Bulletin 71.2:LR125

November 2014

Type LR125 Pressure Reducing Liquid Regulator

• Rugged design

• Reliable

• Thoroughly tested

• Internally actuated

• Compact

• 1, 2, 3, 4 in. body sizes

• Recommended for water

and oil applications

• Full SST construction
available for harsh

environments

• API 614 Compliant

Figure 1. Type LR125 Pressure Reducing Liquid Regulator

Introduction

The Type LR125 pilot-operated, pressure reducing
regulator is designed for liquid industrial/commercial
applications. The Type LR125 provides smooth
operation, tight shutoff and long life. Its internally
actuated metal plug eliminates disadvantages

associated with  exible element style regulators, and
the specially engineered  ow path de ects debris,

protecting the seat from damage and erosion. The
Type LR125 is used in conjunction with a Type MR95H
pilot and Type 112 restrictor. An internal inlet strainer
prevents large particles from entering the main valve,
limiting damage to internal parts.

Features and Bene ts

1

Tight Shutoff—The Type LR125 uses a diaphragm
and metal plug, eliminating the disadvantages of

 exible element style regulators. When open, the
metal plug de ects particles and debris away from

the diaphragm. The result is enhanced resistance to

particle erosion, which provides excellent shutoff over
an extended life. When closed, loading pressure and

the main spring push the diaphragm onto the tapered­edged seat on the cage.

www.fisherregulators.com

D103575X012

Bulletin 71.2:LR125

Specications

The Specications section lists the specications for the Type LR125 regulator. Factory specication is stamped

on the nameplate fastened on the regulator at the factory.

Main Valve Body Sizes, End Connection Styles and

Structural Design Ratings

(1)(2)

See Table 1

Maximum Inlet Pressures

(1)

Type LR125 Main Valve: See Table 1
Type MR95H Pilot: See Table 2
Type 112 Restrictor: 1500 psig / 103 bar
Maximum Outlet Pressure
Type LR125 Main Valve: See Table 1
Type MR95H Pilot: See Table 2

Outlet (Control) Pressure Ranges

See Table 3

Main Valve Plug Travel
1 in. / DN 25: 0.37 in. / 9.4 mm
2 in. / DN 50: 0.68 in. / 17 mm

3 in. / DN 80: 0.98 in. / 25 mm
4 in. / DN 100: 1.19 in. / 30 mm

Main Valve Minimum Differential Pressures

(1)

See Table 5

Temperature Capabilities

(1)

See Table 4

Main Valve Flow Direction

Up through the center of the cage and down
through the cage slots

Main Valve Internal Inlet Strainer Sizes

1 in. / DN 25: 12 Mesh (0.0661 in. / 1.68 mm)

(3)

2, 3 and 4 in. / DN 50, 80 and 100:
10 Mesh (0.0787 in. / 2 mm)

(3)

Regulating Capacities

See Table 11

Flow and IEC Sizing Coefcients

Type LR125 Main Valve: See Table 6
Type MR95H Pilot: See Table 7
Type 112 Restrictor: See Table 8
Pressure Registration

External: 1/2 NPT
Spring Case Vent

Type Y602-12

Approximate Weights

Options

• Pre-piped Pilot Supply

• Travel Indicator

Construction Materials

Type LR125 Main Valve

Body: WCC Steel, CF8M or CF3M Stainless Steel
Bonnet: Steel or Stainless Steel
Bonnet Bushing: Steel or Stainless Steel
Cage: Stainless steel
Spring: Stainless steel

Top Plug: Stainless steel
Bottom Plug: Stainless steel

Internal Inlet Strainer: Stainless steel

Diaphragm: Nitrile (NBR) or Fluorocarbon (FKM)

O-rings: Nitrile (NBR) or Fluorocarbon (FKM)

Flanged Locknut: Stainless Steel
Backup Rings: Polytetrauoroethylene (PTFE)
Upper Spring Seat: Stainless steel
Indicator Protector and Cover: Plastic
Indicator Stem: Stainless steel
Indicator Fitting: Stainless steel
Travel Indicator Plug: Stainless steel

Type MR95H Pilot

Body: WCC Steel or CF8M Stainless Steel
Spring Case: WCC Steel or CF8M Stainless Steel

Orice: Stainless Steel

Diaphragm: Neoprene (CR) or Fluorocarbon (FKM)

Disk: Nitrile (NBR) or Fluorocarbon (FKM)

Mounting Parts

Pilot Mounting Pipe Nipple: Plated steel or
Stainless steel

Pipe Fittings: Plated steel or Stainless steel
Tubing: Stainless Steel

Type 112 Restrictor

Body: 15-5 Stainless Steel
Groove Valve: Stainless steel
Retainer: Stainless steel
Pipe Plug: Stainless steel
O-rings: Nitrile (NBR) or Fluorocarbon (FKM)

See Table 9

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

2. Ratings and end connections other than ASME standards can usually be provided; contact your local Sales Ofce.

3. Nominal sieve opening

2

Debris Protection—The specially engineered ow
path, along with the metal plug, allows ow through the

regulator without seat impingement. The addition of an
internal inlet strainer prevents large particles from entering
the regulator, minimizing damage to internal parts.

3

High Accuracy—Multiple control pressure ranges
offered by Type MR95H pilot and lower accuracy class

2

inherent to pilot operated pressure regulator design
provide the Type LR125 with tight and accurate control.

Long Life—The robust design of the Type LR125 with

4

its metal plug and specially engineered ow path allows
ow through the regulator without seat impingement.

The diaphragm design eliminates the possibility of

taking a “set”, a common problem with exible element

Bulletin 71.2:LR125

TYPE LR125 PRESSURE REDUCING REGULATOR

3

W5092

TYPE MR95H PILOT

10

7

7

W7398

TRIM PACKAGE

11

9

1

TYPE MR95H PILOT

5

6

8

4

12

2

W7344

TYPE LR125 PRESSURE REDUCING REGULATOR

Figure 2. Type LR125 Features and Bene ts

style regulators. To prevent damage, the diaphragm is
fully supported in both the open and closed positions.
These features enable the Type LR125 components to
work longer with less wear and tear.

5

Full Usable Capacity—Fisher® branded regulators
are laboratory tested. One hundred percent of the
published  ow capacity can be used with con dence.

Thorough Laboratory Testing—Emerson Process

6

Management Regulator Technologies, Inc. (Emerson™)
state-of-the-art  ow laboratory allows thorough testing of
all new designs. Tests are conducted on Fisher branded
regulators for performance features such as  ow,

strength, shutoff and material compatibility.

7

Easy In-Line Maintenance—Top-entry design
reduces maintenance time. Trim parts can be
inspected, cleaned and replaced without removing
the body from the pipeline. No special alignment is
required when replacing the diaphragm.

W7345

8

O-ring Design—The Type LR125 uses elastomer

O-rings instead of gaskets, reducing maintenance and

assembly time.

9

In-Service Travel Indicator—The optional travel
indicator responds to the precise movement of the
diaphragm and plug assembly and shows the actual
valve position. The travel indicator makes in-service
inspection and troubleshooting easy. Also, it can be used
for remote alarming and monitoring stem position.

Versatility—The Type LR125 uses the E-body, making

10

available the standard construction materials and end

connections (ASME and EN) used by other E-body

regulators and control valves. Type MR95H can handle
inlet pressures up to 300 psig / 20.7 bar and outlet
pressures from 15 to 150 psig / 1.0 to 10.3 bar.

11

Easy-to-Maintain—The pilot is designed to allow quick
and simple in-line trim inspection and parts replacement.

3

Bulletin 71.2:LR125

TYPE MR95H PILOT

SUPPLY LINE

M1215

INLET PRESSURE

OUTLET PRESSURE

ATMOSPHERIC PRESSURE

LOADING PRESSURE

TYPE 112 RESTRICTOR

CONTROL SPRING

VALVE PLUG

MAIN SPRING

DIAPHRAGM AND
PLUG ASSEMBLY

INTERNAL STRAINER

DIAPHRAGM

TYPE LR125 WITH TYPE MR95H PILOT AND TYPE 112 RESTRICTOR

Figure 3. Type LR125 Operational Schematic

Powder Paint Coating—Carbon steel body is powder

12

paint coated providing superior impact, abrasion and
corrosion resistance.

Pilot Type Description

Type MR95H—High-pressure pressure reducing pilot

for 15 to 150 psig / 1.0 to 10.3 bar outlet pressures.
Designed to handle inlet pressures up to 300 psig /

20.7 bar.

Principle of Operation

As long as the outlet (control) pressure is above the
outlet pressure setting, the pilot valve plug or disk

remains closed (Figure 3). Force from the main spring, in

addition to inlet pressure bleeding through the restrictor,
provide downward loading pressure to keep the main
valve diaphragm and plug assembly tightly shutoff.

When the outlet pressure decreases below the pilot

outlet pressure setting, the pilot plug or disk assembly
opens. Loading pressure bleeds downstream through
the pilot faster than it can be replaced through the
supply line. This reduces loading pressure on top of
the main valve diaphragm and plug assembly and
lets the unbalanced force between inlet and loading
pressure overcome the main spring force to open the
Type LR125 diaphragm and plug assembly.

As the outlet pressure rises toward the outlet pressure
setting, it compresses the pilot diaphragm against
the pilot control spring and lets the pilot valve plug
or disk close. Loading pressure begins to build up
on the Type LR125 diaphragm and plug assembly.
The loading pressure, along with force from the main
spring, pushes the diaphragm and plug assembly onto
the tapered-edge seat, producing tight shutoff.

4