Data Sheet
Bulletin 71.1:627W
October 2009
D102088X012
www.sherregulators.com
Types 627W and 627WH Direct-Operated Pressure
Reducing Liquid Regulators
Introduction
The Types 627W and 627WH are direct-operated pressure
reducing regulators for liquid service. They are available
in NPS 3/4, 1, and 2 (DN 25 and 50) body sizes and in
a wide range of materials of construction to match most
service conditions.
A control line version is available in either the Type 627W or
the Type 627WH (a higher pressure range unit). Both units are
available with either internal or external downstream pressure
registration. A control line is required for the external pressure
registration version. The control line version has a blocked
throat with an O-ring stem seal and a 1/4 NPT control line
connection in the diaphragm case (Figure 2). The stem seal
separates the body outlet pressure from the diaphragm case.
Features
• Application Versatility—The regulators can be used in
nearly all liquid applications where constant downstream
pressure is required.
• 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 simplies disassembly
for maintenance.
• Tamper-Resistant—An adjusting screw locknut
and protective cap (Figure 1) are standard on all
Type 627W regulators to discourage tampering with
the pressure setting.
• Tight Shutoff Capability—A at-faced disk of
Nylon (PA) or various elastomers provides excellent
shutoff capability.
• 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.
The regulator may be installed in any position without
affecting operation as long as the spring case vent is
protected from the elements.
• Versatility—The Types 627W and 627WH are available
in six spring ranges, ve disk materials, and three
different body materials. The body is available in NPT,
ASME anged, and EN anged constructions.
Figure 1. Type 627W Pressure Reducing Liquid Regulator
W6309
Principle of Operation
The Type 627W or 627WH (refer to Figure 2) is a direct-
operated regulator. On the internal registration version,
downstream pressure is registered internally through the body
to the under side of the diaphragm. When the downstream
pressure is at or above the set pressure, the disk is held
against the seat, and there is no ow through the regulator.
When demand increases, downstream pressure drops slightly
allowing the spring to extend, moving the stem down and the
disk away from the seat. This allows ow through the body to
the downstream system.
Types 627W and 627WH direct-operated regulators are also
available in a downstream control line version. This version has
a stem seal between the body outlet pressure and diaphragm
case. Pressure is registered under the diaphragm through the
1/4 NPT downstream control line connection (Figure 2).