Emerson S402Y User's Manual

Instruction Manual
Form 5319

March 2009

Type S402Y

Type S402Y Pressure Reducing Regulator

WARNING

!

Failure to follow these instructions or
to properly install and maintain this
equipment could result in an explosion,

re and/or chemical contamination

causing property damage and personal
injury or death.

Fisher® regulators must be installed,
operated, and maintained in accordance
with federal, state, and local codes,
rules and regulations, and
manufacturer’s instructions.

If the regulator vents gas or a leak
develops in the system, service to
the unit may be required. Failure
to correct trouble could result in a
hazardous condition.

Call a gas service person to service

the unit. Only a qualied person must

install or service the regulator.

Introduction

This installation manual covers the installation and
startup procedures for Type S402Y pressure
reducing regulators.

Figure 1. Type S402Y Pressure Reducing Regulator Assembly

Scope of the Manual

This instruction manual provides information on
installation, maintenance, and replacement parts for
Type S402Y pressure-reduction regulators.

Product Description

The Type S402Y is generally employed in residential
or small commercial applications in order to reduce

gas distribution pressures to a specied pressure

range from 4.5-inches w.c. to 2.5 psig (11,0 mbar to
0,17 bar). The Type S402Y has an integral high
capacity internal relief valve.

The Type S402Y is typically used in residential
or small commercial applications to reduce gas
distribution pressures down to a reduced pressure
range from 4.5-inches w.c. to 2.5 psig (11,0 mbar
to 0,17 bar). The Type S402Y has an integral high
capacity internal relief valve.

www.emersonprocess.com/regulators

Specications

Specications for Type S402Y construction are found

on page 2. The following information is stamped on

the regulator at the factory: Type number, orice size,

spring range, and date of manufacture.

D101838X012

Type S402Y

Specications

Body Size and End Connection Styles

(1)

NPS 3/4 or 1, NPT

Maximum Operating Inlet Pressure

(2)

125 psig (8,6 bar)

Maximum Allowable Emergency Inlet Pressure

175 psig (12,1 bar)

Allowable Outlet Pressures (Casing)

(2)

Emergency: 10 psig (0,69 bar)
Maximum Operating to Avoid Internal Part
Damage: 5 psig (0,35 bar)

Outlet Pressure Ranges

(2)

See Table 2

Orice Sizes

Temperature Capabilities

-20° to 160°F (-29° to 71°C)

Pressure Registration

Internal

(2)

Spring Case Vent Connection

1 NPT with removable screen (standard)
3/4 NPT with removable screen (optional)

Spring Case Vent and Body Mounting Positions

See Figure 5

External Dimensions

See Figure 6

Approximate Weight

4 pounds (2 kg)

(2)

See Table 1

1. End connections threaded to other than ASME standards can usually be supplied.

2. The pressure/temperature limits in this Instruction Manual and any applicable standard or code limitation should not be exceeded.

Table 1. Orice Sizes and Cg Coecients

ORIFICE SIZE

Inches mm Psig bar

1/8

3/16

1/4

1. Maximum operating inlet pressure is 125 psig (8,6 bar) for all orice sizes. The optimum performance is based on 2-inches w.c (5 mbar) boost or 1-inch w.c. (2 mbar) droop.

3,2
4,8
6,4

ORIFICE

COLOR CODE

Blue
Green
Brown

WIDE-OPEN C

RELIEF SIZING

12.5

28.2

50.0

FOR

g

MAXIMUM OPERATING PRESSURE FOR

OPTIMUM PERFORMANCE

125

80
60

(1)

8,6
5,5
4,1

Table 2. Outlet Pressure Ranges and Control Spring Data

OUTLET PRESSURE RANGES

4.5 to 6-inches w.c. (11 to 15 mbar) T13539T0012 Red 0.070 (1,78) 2.50 (63,5)

5.5 to 8-inches w.c. (14 to 20 mbar) T13527T0012 Yellow 0.067 (1,70) 2.59 (65,8)

7.5 to 9.5-inches w.c. (19 to 24 mbar) T13563T0012 Olive drab 0.067 (1,70) 3.24 (82,3)

9.5 to 13-inches w.c. (24 to 32 mbar) T13529T0012 Green 0.075 (1,91) 3.00 (76,2)

13-inches w.c. to 1.5 psig (32 mbar to 0,10 bar) T13564T0012 Unpainted 0.120 (3,05) 1.93 (49,0)

1.5 to 2.5 psig (0,10 to 0,17 bar) T13536T0012 Blue 0.120 (3,05) 2.60 (66,0)

Part Number Color Wire Diameter, Inches (mm) Free length, Inches (mm)

Principle of Operation

CONTROL SPRING DATA

assembly. When downstream demand is reduced, the
pressure under the diaphragm increases. This pressure

Inlet pressure ows through the open orice around

the valve disk and disk holder, around the cam stem

down the remaining length of the orice tube and into

the outlet of the regulator body. However, not all of the
pressure passes directly from the inlet to the outlet of

overcomes the regulator setting (which is set by a
spring) and moves the diaphragm assembly upwards.
This upward motion is transferred to the cam stem which
in turn bears against the sliding contact point on the
back side of the disk holder.

the regulator. Pressure is channelled through openings

in the orice tube and pressurizes the cavity formed by

the body and diaphragm/diaphragm head/cam stem

The inclined surface of the cam then forces the disk

holder toward the orice and reduces gas ow. If a higher

2

INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE

DRILLED CLOSING CAP WITH TRAVEL STOP
TO OPEN RELIEF VALVE

FLAPPER

LOWER CASING

Type S402Y

MAIN SPRING

RELIEF VALVE SPRING

DIAPHRAGM

INLET SCREEN

ORIFICE TUBE ASSEMBLY

M1162

INLET PRESSURE

OUTLET PRESSURE

ATMOSPHERIC PRESSURE

Figure 2. Type S402Y Operational Schematic

volume ow rate is demanded downstream, the pressure

under the diaphragm decreases. The control spring
force pushes the diaphragm/diaphragm head/cam stem
assembly downward and the valve disk moves away

from the orice.

At the lockup (complete shutoff) position the ratio of
the diaphragm travel to disk travel is 4 to 1 giving the
regulator an effective 4 to 1 lever ratio for positive lockup.

The cam stem is characterized for higher downstream

demand to produce a mechanical boost effect.

Type S402Y regulator includes an internal relief valve
for overpressure protection. If the downstream pressure
exceeds the regulator setting and the regulator is not
able to achieve complete shutoff (lockup) due to foreign

matter lodged between the orice and the valve disk

or a failure in the valve disk, the regulator diaphragm
assembly moves upwards trying to push the valve

disk against the orice. The valve disk and disk holder
being pressed against the orice will prevent the cam

stem from being able to travel any further upward in
conjunction with the diaphragm assembly. The continued
leakage of the inlet pressure into the regulator cavity
will then force the diaphragm and diaphragm head up
off of the seating area of the relief valve overcoming

CAM STEM

DISK HOLDER ASSEMBLY

VALVE DISK

the relief valve spring which was pressing them
together. The resulting gap will allow pressure to exit the
regulator cavity and exhaust through the openings in the
diaphragm head and out the spring case vent
to atmosphere.

Installation

WARNING

!

Personal injury, equipment damage, or
leakage due to escaping accumulated
gas or bursting of pressure-containing
parts may result if this regulator is
overpressured or is installed where
service conditions could exceed the

limits given in Specication Section.

To avoid such injury or damage, provide
pressure-relieving or pressure-limiting
devices (as required by Title 49, Part 192,
of the U.S. Code of Federal Regulations,
by the National Fuel Gas Code Title 54 of
the National Fire Codes of the National
Fire Protection Association, or by other

3