Emerson 627 Data Sheet

Bulletin 71.1:627

627 Series Pressure Reducing Regulators

Introduction

The 627 Series direct-operated pressure reducing
regulators (Figure 1) are for low and high-pressure
systems. These regulators can be used with natural
gas, air, or a variety of other gases. Performance
characteristics vary according to construction (see the

Specications section).

Features

• Internal Relief Valve—Types 627R, 627LR, and
627MR regulators have an internal relief valve, which
in many cases eliminates the usual requirement for
an external relief valve, thereby reducing equipment

and maintenance costs. Refer to the Specications

section for performance data.

March 2013

• Types 627R, 627LR, and 627MR Travel Stop— The
internal relief valve still works if the disk or linkage fails.
The pusher post (Figure 6) contacts the travel stop of
the lever retainer and, as the diaphragm continues to
rise, it opens the relief valve.

• Relief Operation Indicator—A rubber cap (Figure 7)
slipped on the vent assembly pops off when the relief
valve opens, indicating the relief valve has opened
since the last inspection.

• Easy to Maintain—Trim parts can be replaced without
removing the regulator body from the pipeline. A
two-bolt connection between the body and diaphragm

casing simplies disassembly for maintenance.

• Installation Adaptability—The diaphragm case and/
or regulator body can be rotated in any of four positions
to allow regulator installation in locations with limited
space (Figure 8). The regulator may be installed in
any position without affecting operation as long as the
spring case vent is protected from the elements.

• Application Versatility—The different 627 Series
constructions can be used as farm tap regulators,
regulator-relief valves, monitoring regulators, or
high-pressure industrial regulators.

W4793

Figure 1. Typical 627 Direct-Operated Pressure
Reducing Regulator

• Extended Body Option—The Type 627 Long Body
is available with same face-to-face dimensions as the
Type 630 with threaded NPT end connections.

• Tamper-Resistant—An adjusting screw locknut and
protective cap (Figure 2) is standard on all
627 Series regulators to discourage tampering with
the pressure setting.

• Wide Range of Flow Capabilities—A selection of

body sizes and orice sizes is available to satisfy
various ow requirements.

• Tight Shutoff Capability—A at-faced disk of
Nitrile (NBR), Nylon (PA), or Fluorocarbon (FKM)
provides excellent shut-off capability.

www.fisherregulators.com

D101331X012

Bulletin 71.1:627

Specications

The Specications section gives some general specications for the 627 Series regulators. The nameplates give

detailed information for a particular regulator as it comes from the factory.

Available Constructions
Type 627: Direct-operated pressure reducing

regulator equipped with a pitot tube for greater
regulated capacities (Figure 2).
Type 627R: Type 627 with internal relief and open
throat (Figure 3).
Type 627LR: Type 627R with light rate relief spring
(Figure 3).
Type 627M: Type 627 with a stem seal between the
body outlet pressure and diaphragm case. Pressure
is measured under the diaphragm through the 1/4 NPT
downstream control line connection (Figure 2).

Type 627MR: Type 627M with internal relief (Figure 4).
Type 627H: Type 627 with a diaphragm limiter to deliver

a higher outlet pressure (Figure 5).
Type 627HM: Type 627H with a stem seal between the
body outlet pressure and diaphragm case. Pressure
is measured under the diaphragm through the 1/4 NPT
downstream control line connection (Figure 5).

BodySizesandEndConnectionStyles

BODY SIZE

NPS DN

3/4 - - - - NPT

1 25

2 50

END CONNECTION STYLE

NPT, CL150 RF, CL300 RF,

CL600 RF, and Long Body

NPT, CL150 RF, CL300 RF,

CL600 RF, and Long Body

Maximum Inlet Pressure

(1)

(Body Rating)

CONSTRUCTION

AVAILABLE

All

NPT Stainless Steel: 2000 psig / 138 bar
Flanged Stainless Steel: 1440 psig / 99.3 bar
NPT Steel: 2000 psig / 138 bar
Flanged Steel: 1500 psig / 103 bar
Ductile Iron: 1000 psig / 69.0 bar

Maximum Valve Disk Inlet Pressure Rating

(1)

Nylon (PA) Disk: 2000 psig / 138 bar
Nitrile (NBR) Disk: 1000 psig / 69.0 bar
Fluorocarbon (FKM) Disk: 300 psig / 20.7 bar

Maximum Operating Inlet and Outlet
Pressure Ranges

See Table 2 for pressures by orice size and

(1)

spring range

Maximum Spring and Diaphragm Casing Pressure

See Table 3

Maximum Body Outlet Pressure

(1)(2)

(Types 627M,

627MR, and 627HM Only)

NPT Steel: 2000 psig / 138 bar
Flanged Steel: 1500 psig / 103 bar
Ductile Iron: 1000 psig / 69.0 bar

OriceSizes

See Table 2

Internal Relief Performance

Type 627R: See Table 4 and Figure 9
Type 627LR: See Table 5
Type 627MR: Limited by eld-installed control
line piping

Regulator Capacities

Type 627, 627M, or 627MR: See Tables 6 to 9
Type 627H or 627HM: See Tables 10 to 12
Type 627R: See Tables 13 to 14

FlowCoefcients

See Table 15

IECSizingCoefcients

See Table 16

Construction Materials

Body: Ductile iron, WCC steel, stainless steel
Spring Case and Diaphragm Case: WCC steel,
stainless steel, ductile iron, or die cast aluminum
Orice: Aluminum (standard) or stainless steel
Disk Holder with Valve Disk:

2000 psig / 138 bar Maximum Pressure:

Aluminum or stainless steel with Nylon (PA)

1000 psig / 69.0 bar Maximum Pressure:

Aluminum (standard) or stainless steel
with Nitrile (NBR)

300 psig / 20.7 bar Maximum Pressure:
Stainless steel or aluminum with

Fluorocarbon (FKM) disk
O-Rings:
Nitrile (NBR) or Fluorocarbon (FKM)
Diaphragm:

Types 627H and 627HM: Neoprene(CR)
All Others: Nitrile (NBR) or Fluorocarbon (FKM)

(1)

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

2. Types 627, 627H, 627R, and 627LR are limited by maximum diaphragm casing pressure.

- continued -

2

Specications(continued)

Bulletin 71.1:627

Relief Indicator

For Types 627R, 627LR, and 627MR (see Figure 7)

Elastomer Temperature Capabilities

MATERIAL

Nitrile (NBR)

Fluorocarbon (FKM)

Nylon (PA) Disk -40 to 180 -40 to 82

Neoprene (CR) for

Types 627H and

627HM only

DISK/

DIAPHRAGM

Disk

Dipahragm

Disk

Diaphragm

Diaphragm -40 to 180 -40 to 82

(1)(3)

TEMPERATURE

°F °C

-40 to 180 -40 to 82

0 to 180 -18 to 82

Pressure Registration

Type 627, 627H, 627R, or 627LR: Internal
Type 627M, 627HM, or 627MR: External through
1/4 NPT internal control line connection in the
diaphragm casing

De-Icer System

See Figure 10 and Type 627M De-Icer System
Application section

Spring Case Orientation and Vent Location

See Figure 8

Spring Case Vent Connection

3/4 NPT with removable screened vent assembly

Approximate Weight

Ductile Iron, Steel, or Stainless Steel Casings:
10 pounds / 5 kg
Aluminum Casing: 6.3 pounds / 3 kg

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

3. Stainless steel body is rated to -40°F / -40°C. Steel and Ductile Iron bodies are rated to -20°F / -29°C.

Principle of Operation

Refer to Figures 2 through 5. When downstream demand
decreases, the pressure under the diaphragm increases.
This pressure overcomes the regulator setting (which is
set by a spring). Through the action of the pusher post
assembly, lever, and valve stem the valve disk moves

closer to the orice and reduces gas ow. If demand

downstream increases, pressure under the diaphragm
decreases. Spring force pushes the pusher post
assembly downward and the valve disk moves away from

the orice allowing more ow through the body to the

downstream system.

Product Description

Types 627 and 627H Direct-Operated Pressure
Reducing Regulators

The Types 627 and 627H regulators provide economical
pressure reducing control for a variety of residential,
commercial, and industrial applications. The regulator
pitot tube located in a high velocity stream provides
dynamic boost that compensates for outlet pressure drop
(see Tables 6 through 12).

Type 627 Long Body

the Type 627R, 627LR, or 627MR regulator, the internal
relief across the diaphragm (Figure 3 or 4) provides
overpressure protection in many applications. As outlet
pressures build-up above the start-to-discharge point, the
diaphragm moves off the relief valve seat allowing the
excess pressure to bleed out through the screened vent.

For extra protection, should failure conditions exist which
would prevent normal operation of the regulator (for
example, disk broken off, or disk erosion), the pusher
post contacts the lever retainer (Figure 6) causing the
relief valve assembly to open. Since the diaphragm
continues to rise as downstream pressure builds, it opens
the relief valve, thereby opening the valve. This internal
relief may be adequate for the application.

Downstream Control Line for Type 627M, 627HM, or
627MR Regulator

A Type 627M, 627HM, or 627MR regulator has a blocking
throat stem seal with O-rings and a 1/4 NPT control line
connection in the diaphragm case (Figure 4). A regulator
with a downstream control line is used for monitoring
applications or other applications where other equipment
is installed between the regulator and the pressure control
point. The stem seal separates the body outlet pressure
from the diaphragm case.

The Type 627 Long Body regulator can be used as a
drop-in replacement for existing Type 630 installations
without the need to modify piping.

Internal Relief for Type 627R, 627LR, or
627MR Regulator

The Types 627R and 627LR internal relief performance
values (Tables 4 and 5) were obtained by removing the

disk assembly from the regulator, see Figure 9. For

Installation

Regulator operation within ratings does not preclude
the possibility of damage from debris in the lines or from
external sources. A regulator should be inspected for
damage periodically and after any overpressure condition.
Ensure that the operating temperature capabilities listed in

Specications section are not exceeded.

3

Bulletin 71.1:627

MXXXX

Type XXXX

MXXXX

Type 627R

MXXXX

Type 627M

ADJUSTING
SCREW CAP

LOCKNUT

ADJUSTING
SCREW

SPRING CASE

CONTROL SPRING

1/4 NPT
CONTROL LINE
CONNECTION

SCREENED
VENT
ASSEMBLY

W4684-2

PUSHER
POST

DIAPHRAGM CASING

PITOT TUBE

DISK ASSEMBLY

Figure 2. Types 627 and 627M Operational Schematics

W4683-2

BLOCKING THROAT STEM SEAL

ORIFICE

DETAILS OF TYPE 627M

LARGE OPENING
FOR RELIEF

W4679-2

INTERNAL RELIEF FLOW PATH

Figure 3. Types 627R and 627LR Operational Schematics

4

PUSHER POST

LEVER RETAINER

LEVER

W4681-2

RELIEF
VALVE
SPRING

INTERNAL RELIEF VALVE

Bulletin 71.1:627

MXXXX

Type 627MR

Type 627MR

MXXXX

Type 627HM

MXXXX

Type XXXX

1/4 NPT

W4682-2

CONTROL LINE CONNECTION

INTERNAL RELIEF FLOW PATH

Figure 4. Type 627MR Operational Schematics

ADJUSTING
SCREW CAP

ADJUSTING SCREW

SCREENED VENT
ASSEMBLY

DIAPHRAGM
LIMITER

DIAPHRAGM
LIMITER
O-RING

PUSHER POST
O-RINGS

PUSHER POST

SPRING CASE

CONTROL SPRING

DIAPHRAGM HEAD

W4680-2

1/4 NPT
CONTROL LINE
CONNECTION

W5482-1

PITOT TUBE

ORIFICE

INTERNAL
RELIEF
VALV E

BLOCKING
THROAT STEM SEAL

BLOCKING THROAT
STEM SEAL

DETAILS OF TYPE 627HM

DIAPHRAGM
CASING

W5483-1

Figure 5. Types 627H and 627HM Operational Schematics

DISK ASSEMBLY

5

Bulletin 71.1:627

LEVER
RETAINER

PUSHER
POST

TRAVEL STOP

W4666-1

Figure 6. Internal Relief Construction Feature Figure 7. Relief Indicator

Table 1. Maximum Cold Working Pressure of Body Inlet (Body Rating)

BODY SIZE

NPS DN psig bar

3/4 20

1
2

1
2

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

2. Temperature may decrease these maximum pressures.

25
50

25
50

BODY MATERIAL END CONNECTION

Ductile iron NPT 1000 69.0

Steel NPT 2000 138

Stainless Steel NPT 2000 138

Ductile iron NPT 1000 69.0

Steel

Stainless Steel

W4665-1

(1)(2)

MAXIMUM INLET PRESSURE

NPT 2000 138
CL150 RF 290 20.0
CL300 RF 750 51.7
CL600 RF 1500 103

PN 16/25/40 580 40.0

CL150 RF 275 19.0
CL300 RF 720 49.6
CL600 RF 1440 99.3

PN 16/25/40 580 40.0

RELIEF
INDICATOR CAP

Note

If the regulator is shipped mounted on
another unit, install that unit according
to the appropriate Instruction manual.

Overpressure Protection

627 Series regulators have outlet pressure ratings that are
lower than their inlet pressure ratings. A pressure-relieving
or pressure-limiting device must be provided by the user
for the Types 627, 627H, 627M, and 627HM regulators if
the inlet pressure can exceed the outlet pressure rating,
since these regulators do not have internal relief.

Types 627R and 627LR regulators provide internal
relief which limits the total outlet pressure build-up over
setpoint. Use Table 4 or 5 and the following example
to determine the maximum inlet pressure allowed to
keep the maximum allowable downstream pressure
from being exceeded.

Given:

Desired outlet pressure setting : 40 psig / 2.8 bar
Maximum allowable

downstream pressure

Orice size

: 125 psig / 8.6 bar

: 1/4 inch / 6.35 mm

What is the maximum inlet pressure?

Control spring range

(rst column)

Outlet pressure setting

(second column)

Maximum allowable

downstream pressure

(third column)

Orice size column across from

the 125 psig

maximum allowable pressure
and the column under

1/4-inch / 6.4 mm orice size

/ 8.6 bar

: 35 to 80 psig /

2.4 to 5.5 bar

: 40 psig / 2.8 bar

: 125 psig / 8.6 bar

: 1/4 inch / 6.4 mm

From Table 4, the maximum inlet pressure for this example
is 300 psig / 20.7 bar.

In many cases the internal relief of Types 627R and
627LR offers full capacity overpressure protection.
No additional relief capacity is needed if the actual inlet
pressure is equal to or less than the inlet pressure shown
under the Maximum Inlet Pressure column heading in
Tables 4 and 5.

If the maximum allowable downstream system pressure is
less than any of the pressures shown in the third column

6

Bulletin 71.1:627

Table 2. Maximum Inlet Pressures and Outlet Pressure Ranges

OUTLET PRESSURE

TYPE

627
and

(3)

627M

627R

and

627MR

627LR

627H

and

(3)

627HM

1. For inlet pressure in excess of 1000 psig / 69.0 bar, refer to the maximum body and disk pressure ratings in the Specications section.

2. For pressure settings under 10 psig / 0.69 bar, inlet pressure should be limited to approximately 100 psig / 6.9 bar so the setpoint adjustment can be obtained.

3. The unbalance forces change from the wide-open monitor mode to an active regulator mode such that the Type 627M or 627HM should have a 3/8 inch / 9.5 mm or larger orice.

- Shaded areas indicate that Fluorocarbon (FKM) and Nylon (PA) disk material are not available.

RANGE, SPRING PART

NUMBER, AND

COLOR CODE

(2)

5

to 20 psig /

0.34 to 1.4 bar

10B3076X012

Yellow

15 to 40 psig /

1.0 to 2.8 bar

10B3077X012

Green

35 to 80 psig /

2.4 to 5.5 bar

10B3078X012

Blue

70 to 150 psig /

4.8 to 10.3 bar

10B3079X012

Red

(2)

5

to 20 psig /

0.34 to 1.4 bar

10B3076X012

Yellow

15 to 40 psig /

1.0 to 2.8 bar

10B3077X012

Green

35 to 80 psig /

2.4 to 5.5 bar

10B3078X012

Blue

70 to 150 psig /

4.8 to 10.3 bar

10B3079X012

Red

15 to 40 psig /

1.0 to 2.8 bar

10B3077X012

Green

140 to 250 psig /

9.7 to 17.2 bar

10B3078X012

Blue

240 to 500 psig /

16.5 to 34.5 bar

10B3079X012

Red

ORIFICE SIZE

Inches mm psig bar psig bar psig bar

3/32

1/8

3/16

1/4
3/8
1/2

3/32

1/8

3/16

1/4
3/8
1/2

3/32

1/8

3/16

1/4
3/8
1/2

3/32

1/8

3/16

1/4
3/8
1/2

3/32

1/8

3/16

1/4
3/8
1/2

3/32

1/8

3/16

1/4
3/8
1/2

3/32

1/8

3/16

1/4
3/8
1/2

3/32

1/8

3/16

1/4
3/8
1/2

3/32

1/8

3/16

1/4

3/32

1/8

3/16

1/4
3/8
1/2

3/32

1/8

3/16

1/4
3/8
1/2

2.4

3.2

4.8

6.4

9.5
13

2.4

3.2

4.8

6.4

9.5
13

2.4

3.2

4.8

6.4

9.5
13

2.4

3.2

4.8

6.4

9.5
13

2.4

3.2

4.8

6.4

9.5
13

2.4

3.2

4.8

6.4

9.5
13

2.4

3.2

4.8

6.4

9.5
13

2.4

3.2

4.8

6.4

9.5
13

2.4

3.2

4.8

6.4

2.4

3.2

4.8

6.4

9.5
13

2.4

3.2

4.8

6.4

9.5
13

Nylon (PA) Disk Nitrile (NBR) Disk Fluorocarbon (FKM) Disk

2000
1000

750
500
300
250

2000
1500
1000

750
500
300

2000
2000
1750
1500
1000
750

2000
2000
2000
1750
1250

750

2000
1000

750
500
300
200

2000
1500
1000

750
300
200

2000
1750
1000

750
300
200

2000
1000

500
300
200
200

2000
2000
1750
1500
1000

750

2000
2000
1750
1500
1000

750

MAXIMUM INLET PRESSURE

138

69.0

51.7

34.5

20.7

17.2
138

103

69.0

51.7

34.5

20.7
138

138
121
103

69.0

51.7
138

138
138
121

86.2

51.7
138

69.0

51.7

34.5

20.7

13.8
138

103

69.0

51.7

20.7

13.8
138

121

69.0

51.7

20.7

13.8
138

69.0

34.5

20.7

13.8

13.8

138
138
121
103

69.0

51.7
138

138
121
103

69.0

51.7

1000
1000

750
500
300
250

1000
1000
1000

750
500
300

1000
1000
1000
1000
1000

750

1000
1000
1000
1000
1000

750

1000
1000

750
500
300
200

1000
1000
1000

750
300
200

1000
1000
1000

750
300
200

1000
1000

500
300
200
200

1000
1000

750
500

1000
1000
1000
1000

750
500

1000
1000
1000
1000
1000

750

69.0

69.0

51.7

34.5

20.7

17.2

69.0

69.0

69.0

51.7

34.5

20.7

69.0

69.0

69.0

69.0

69.0

51.7

69.0

69.0

69.0

69.0

69.0

51.7

69.0

69.0

51.7

34.5

20.7

13.8

69.0

69.0

69.0

51.7

20.7

13.8

69.0

69.0

69.0

51.7

20.7

13.8

69.0

69.0

34.5

20.7

13.8

13.8

69.0

69.0

51.7

34.5

69.0

69.0

69.0

69.0

51.7

34.5

69.0

69.0

69.0

69.0

69.0

51.7

(1)

300
300
300
300
300
250

300
300
300
300
300
300

300
300
300
300
300
300

300
300
300
300
300
300

300
300
300
300
300
200

300
300
300
300
300
200

300
300
300
300
300
200

300
300
300
300
200
200

300
300
300
300

20.7

20.7

20.7

20.7

20.7

17.2

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

20.7

13.8

20.7

20.7

20.7

20.7

20.7

13.8

20.7

20.7

20.7

20.7

20.7

13.8

20.7

20.7

20.7

20.7

13.8

13.8

20.7

20.7

20.7

20.7

7

Bulletin 71.1:627

C

D (STANDARD)F

E

SPRING CASE

VENT LOCATION

10B7447-C
A3726

Figure 8. 627 Series Spring Case and Vent Location

POSITION 1

(STANDARD FOR

NPT CONNECTION)

of Tables 4 and 5, use a separate relief valve or a monitor
regulator since the internal relief will not open at pressures
lower than shown in the table.

If the actual inlet pressure is higher than the pressure
shown, in the Maximum Inlet Pressure column, to protect
to the level shown, an additional relief valve is needed to
supplement the relief capacity of the Type 627R or 627LR
internal relief or a full capacity separate relief valve or
monitor regulator may be used.

To size a supplemental relief valve to use with the
Type 627R or 627LR:

1. Use the universal sizing equation to calculate the
wide-open capacity of the regulator port (Q

a. Actual inlet pressure (P

), psia

1

) using:

1

b. Maximum allowable downstream system

pressure (P

c. C

from Table 15

g

) from Table 4 or 5, column 3

2

2. Use the universal sizing equation to calculate the

internal relief  ow (Q

a. Maximum inlet pressure (P

) using:

2

) from Table 4

1

columns 4 through 9 for Type 627R or Table 5
columns 4 through 7 for Type 627LR (use the
pressure from the table even though the actual
pressure will be higher). Remember the equation
requires pressures to be converted to psia.

b. Maximum allowable downstream system

pressure (P

c. C

from Table 15

g

) from Table 4 or 5

2

3. Calculate supplemental relief capacity:

a. Q supplemental relief = Q

1

– Q

2

POSITION 2

BODY-SPRING CASE ORIENTATION

POSITION 3

(STANDARD FOR

FLANGED BODIES)

POSITION 4

Example:

Outlet pressure setting : 10 psig / 0.69 bar
Maximum allowable downstream : 60 psig / 4.1 bar

system pressure

Inlet pressure : 300 psig / 20.7 bar

Ori ce size :

1/4 inch / 6.4 mm

Step 1.

= 300 psig / 20.7 bar

P

1

P2 = 60 psig / 4.1 bar
Cg, 1/4-inch / 6.4 mm

ori ce

= 50

Q1 = 20,300 SCFH / 544 Nm3/h

Step 2.
P

= 190 psig / 13.1 bar

1

P2 = 60 psig / 4.1 bar
Cg, 1/4-inch / 6.4 mm

ori ce

= 50

Q2 = 13,200 SCFH / 354 Nm3/h

Step 3.
Q supplemental relief = Q

– Q

1

2

Q supplemental relief = 20 300 – 13 200 = 7100 SCFH /
544 - 354 = 190 Nm3/h

Overpressurizing any portion of a regulator or associated
equipment may cause personal injury, leakage, or property
damage due to bursting of pressure-containing parts or
explosion of accumulated gas.

If needed, provide appropriate pressure-relieving or
pressure-limiting devices to ensure that none of the

speci cations are exceeded. Regulator operation within

ratings does not prevent the possibility of damage from
external sources such as debris in the pipeline.

Refer to the relief sizing coef cients in Table 15 and the

Capacity Information section to determine the required
external relief valve capacity.

8

200 /

13.8

180 /

12.4

120 /

8.3

psig / bar

2,

80.0 /

5.5

VALVE P

REGULATOR TEST DATA

NPS 1 / DN 25 TYPE 627R
1/8-Inch / 3.18 mm ORIFICE

15 TO 40 psig / 1.0 to 2.8 bar
SPRING RANGE

SETPOINT:
P1 = 80 psig / 5.5 bar
P2 = 40 psig / 2.8 bar

Bulletin 71.1:627

REGULATOR VALVE DISK
ASSEMBLY REMOVED AFTER
MAKING SETPOINT

WITH REGULATOR
BLOCKED WIDE-OPEN
AFTER MAKING SETPOINT

40.0 /

2.8

0

Figure 9. Relief Testing Methods, Outlet vs. Inlet Pressures

START TO BUBBLE

RESEAT

400 /

27.6

800 /

55.2

1200 /

82.7

VALVE P1, psig / bar

Capacity Information

Natural gas regulating capacities at selected inlet
pressures and outlet pressure settings are given in
Tables 6 to 9 for the Type 627 or 627M, in Tables 10 to 12
for the Type 627H, and in Tables 13 to 14 for the
Type 627R regulators. Flows are in SCFH (60°F and

14.7 psia) and Nm3/h (0°C and 1.01325 bar) of 0.6

specic gravity natural gas.

To determine the equivalent capacities for other gases,
multiply the table capacity by the following appropriate
conversion factor: 0.775 for air, 0.789 for nitrogen, 0.628
for propane, or 0.548 for butane. For gases of other

specic gravities, multiply the given capacity by 0.775, and
divide by the square root of the appropriate specic gravity.

Then, if capacity is desired in Nm3/h at 0°C and

1.01325 bar, multiply the values in SCFH by 0.0268.

To determine wide-open ow capacities for relief sizing

use the following formula:

1600 /

110

2000 /

138

2400 /

165

2800 /

193

3200 /

221

where,

Q = gas ow rate, SCFH
G = specic gravity of the gas

T = absolute temperature of gas at inlet, °Rankine
Cg = gas sizing coefcient
P1 = absolute inlet pressure, psia
C1 = ow coefcient (Cg ÷ Cv)
P = pressure drop across the regulator, psi

To obtain the published capacities, the inlet and outlet
piping should be the same as the regulator size.

Q

520

=

CgP1SIN

GT

3417

)

C

P

P

1

DEG

)

1

9

Bulletin 71.1:627

Table 3. Maximum Spring and Diaphragm Casing Pressure

MAXIMUM PRESSURE DESCRIPTION

Maximum pressure to spring and diaphragm

casings to prevent leak to atmosphere other than

relief action (internal parts damage may occur)

Maximum pressure to spring and diaphragm

casings to prevent burst of casings during

abnormal operation (leak to atmosphere and

internal parts damage may occur)

Maximum diaphragm casing overpressure (above

setpoint) to prevent damage to internal parts

1. If the spring case is pressurized, a metal adjusting screw cap is required. Contact your local Sales Ofce for details.

Table 4. Type 627R Internal Relief Performance

OUTLET

PRESSURE

RANGE, SPRING

PART NUMBER,

AND COLOR CODE

(3)

5

to 20 psig /

0.34 to 1.4 bar

10B3076X012

Yellow

15 to 40 psig /

1.0 to 2.8 bar

10B3077X012

Green

1. The internal relief performance values are obtained by removing the disk assembly.

2. For inlet pressures in excess of 1000 psig / 69.0 bar, refer to the maximum body and disk pressure ratings in the Specications section.

3. For pressure settings under 10 psig / 0.69 bar, inlet pressure should be limited to approximately 100 psig / 6.9 bar so the setpoint adjustment can be obtained.

- Shaded areas indicate maximum inlet pressures allowed during system malfunction only. Table 1 gives the maximum inlet pressure for normal regulator operation.

OUTLET

PRESSURE

SETTING

psig bar psig bar psig bar psig bar psig bar psig bar psig bar psig bar

10 0.69

15 1.0

20 1.4

15 1.0

20 1.4

30 2.1

40 2.8

MAXIMUM

ALLOWABLE

DOWNSTREAM

SYSTEM

PRESSURE

60
100
125
175

200
250

60
100
125
175

200
250

60
100
125
175

200
250

60
100
125
175

200
250

60
100
125
175

200
250

100
125
175

200
250

100
125
175

200
250

DIAPHRAGM

CASING MATERIAL

Die cast aluminum

Ductile iron

Steel or Stainless steel 250 17.2 800 55.2

Die cast aluminum 375 25.9 375 25.9 Not Available Not Available

Ductile iron 465 32.1 465 32.1 465 32.1 465 32.1

Steel or Stainless steel 1500 103 1500 103 1500 103 1500 103 1500 103

All materials 60 4.1 120 8.3 60 4.1 120 8.3 120 8.3

(1)

4.1

6.9

8.6

12.1

13.8

17.2

4.1

6.9

8.6

12.1

13.8

17.2

4.1

6.9

8.6

12.1

13.8

17.2

4.1

6.9

8.6

12.1

13.8

17.2

4.1

6.9

8.6

12.1

13.8

17.2

6.9

8.6

12.1

13.8

17.2

6.9

8.6

12.1

13.8

17.2

(1)

TYPE 627

psig bar psig bar psig bar psig bar psig bar

250 17.2 250 17.2

MAXIMUM INLET PRESSURE TO KEEP MAXIMUM ALLOWABLE DOWNSTREAM

3/32 / 2.4 1/8 / 3.2 3/16 / 4.8 1/4 / 6.4 3/8 / 9.5 1/2 / 13

1250

86.2
138
138
138
138
138

69.0
138
138
138
138
138

58.6
138
138
138
138
138

69.0
138
138
138
138
138

43.4
138
138
138
138
138

138
138
138
138
138

103
138
138
138
138

740
1500
1900
2000
2000
2000

620
1400
1900
2000
2000
2000

490
1300
1800
2000
2000
2000

380
1300
1800
2000
2000
2000

200
1200
1700
2000
2000
2000

950
1500
2000
2000
2000

700
1300
1800
2000
2000

2000
2000
2000
2000
2000

1000
2000
2000
2000
2000
2000

850
2000
2000
2000
2000
2000

1000
2000
2000
2000
2000
2000

630
2000
2000
2000
2000
2000

2000
2000
2000
2000
2000

1500
2000
2000
2000
2000

TYPES 627R

AND 627LR

SYSTEM PRESSURE FROM BEING EXCEEDED

OriceSize,Inches/mm

51.0

320

103

620

131

830

138

1100

138

1300

138

1600

42.7

260

96.5

610

131

810

138

1100

138

1300

138

1600

33.8

210

89.6

600

124

800

138

1100

138

1300

138

1600

26.2

210

89.6

590

124

800

138

1100

138

1300

138

1600

13.8

150

82.7

550

117

760

138

1100

138

1300

138

1600

65.5

450

103

670

138

1000

138

1200

138

1600

48.3

330

89.6

560

124

1000

138

1200

138

1600

TYPE 627M TYPE 627MR

Not Available

250 17.2

22.1

190
390
480
670
770
960

170
370
480
670
770
960

130

360
480
670
770
960

130
350
470
640
780
960

100
330
450
630
770
960

260
400
610
760
970

200
340
550
730
970

13.1

26.9

33.1

46.2

53.1

66.2

11.7

25.5

33.1

46.2

53.1

66.2

9.0

24.8

33.1

46.2

53.1

66.2

9.0

24.1

32.4

44.1

53.8

66.2

6.9

22.8

31.1

43.4

53.1

66.2

17.9

27.6

42.1

52.4

66.9

13.8

23.4

37.9

50.3

66.9

42.7

57.2

75.8

89.6
110

17.9

42.1

55.8

75.8

89.6
110

14.5

41.4

55.2

75.8

89.6
110

14.5

40.7

55.2

75.8

89.6

66.2

10.3

37.9

52.4

75.8

89.6

66.2

31.1

46.2

69.0

82.7
110

22.8

38.6

69.0

82.7
110

Not Available Not Available

95
180
220
320
360
450

90
170
220
320
360
450

80
170
220
320
360
450

80
170
220
320
370
450

70
160
210
320
360
460

140
190
300
360
460

120
180
290
350
460

TYPES 627H

AND 627HM

Not Available

(2)

6.6

75
130
160
220
260
320

70
130
160
220
260
320

65
120
160
220
260
320

65
120
160
220
260
320

65
120
160
220
260
320

110
150
220
260
320

108
140
220
250
320

5.2

9.0

11.0

15.2

17.9

22.1

4.8

9.0

11.0

15.2

17.9

22.1

4.5

8.3

11.0

15.2

17.9

22.1

4.5

8.3

11.0

15.2

17.9

22.1

4.5

8.3

11.0

15.2

17.9

22.1

7.6

10.3

15.2

17.9

22.1

7.4

9.7

15.2

17.2

22.1

12.4

15.2

22.1

24.8

31.0

6.2

11.7

15.2

22.1

24.8

31.0

5.5

11.7

15.2

22.1

24.8

31.0

5.5

11.7

15.2

22.1

25.5

31.0

4.8

11.0

14.5

22.1

24.8

31.7

9.7

13.1

20.7

24.8

31.7

8.3

12.4

20.0

24.1

31.7

10

- continued -