CROSBY
STYLE HSL SAFETY VALVES
INSTALLATION, MAINTENANCE AND ADJUSTMENT INSTRUCTIONS
© 2017 Emerson. All Rights Reserved.
Before installation, these instructions must be carefully read and understood
1 INTRODUCTION
Crosby Style HSL is a full nozzle reaction
type safety valve designed for saturated and
superheated steam service. The design is
suitable for set pressures to 725 psig (50 barg)
and temperatures to 1000°F (538°C), with high
capacities, two choices of inlet flange ratings
and simplicity of design to facilitate ease of
maintenance.
The HSL design meets the requirements
of ASME Code Section I, (power boilers)
and relieving capacities are certified by the
National Board of Boiler and Pressure Vessel
Inspectors. Style HSL may also be used in
steam service applications covered by ASME
code section VIII requirements.
2 SPARE PARTS
Emerson recommends spare parts as shown
on Figures 1 and 2. When ordering spare parts,
the valve size, style and serial number should
be given together with set pressure, part name,
and reference number from Figure 1 or 2.
Spare parts may be ordered from any Emerson
regional sales office or authorized Emerson
sales representative.
VCIOM-03104-EN 22/03
Engineering doc. nr.: IS V3187
Centering of the disc through the low friction
guide ensures the HSL opens precisely at set
pressure, even after repeated cycling. The
single bonnet design utilized in both inlet flange
ratings allows set pressure changes without
the need to change-out any components other
than the spring.
Style HSL safety valves are available with
optional test gags, weather hoods for outdoor
applications and Class 150# drip pan elbows.
Ring type joint inlet connection is also available.
The entire HSL range of F thru Q orifices uses
a full nozzle design (Figure 1) to facilitate
removal and ease of maintenance compared
to semi-nozzle designs.
Details of the HSL valve design, materials of
construction, pressure-temperature ratings
and dimensions are provided in Crosby
technical datasheet VCTDS-00595.
Style HSL safety valves incorporate the
Crosby FLEXI-DISC
®
design which is recessed
for pressure and temperature equalization
ensuring a tight seal capable of containing
system pressure at 94% of the valve set
pressure. Seat tightness testing at the factory
for Style HSL safety valves is conducted at 93%
of set pressure.
