3
K109i
AUG 2015
When a dual pressure-relief system is being put into service,
the three-way valve stem should be positioned so that only
one valve is exposed to pressure. While the valve can be
either frontseated (front port is closed) or backseated (back
port is closed), the backseated position is recommended
because it takes pressure off the packing and reduces the
possibility of packing leaks.
Vent the relief valve exit to a safe outdoor location in an
approved manner away from people and building openings.
Do not install valves in a refrigerated space unless
precautions are taken to prevent moisture migration into
the valve body or the relief vent line. Avoid trapped ice
build-up between valves and other equipment.
Only apply thread sealing compound to external pipe threads
and use a modest amount to avoid getting compound inside
the valve. Use brackets or hangers to support the pipe and
prevent the valve from being overly stressed. Do not put
undue stress on the valve by using it to stretch or align pipe.
Pressure test all valves and related piping for leaks. When
testing a dual pressure-relief system, the three-way valve
stem should be in the mid position (only during testing),
ensuring that all valves are properly leak tested. Do not
discharge valves prior to installation or when pressure
testing. Never attempt to reset or change the valve setting.
Always replace pressure-relief valves once they have
discharged.
SERVICE AND MAINTENANCE
These tamper-resistant pressure-relief valves are accurately
factory set and do not require any field adjustments
whatsoever. They are intended for one time over-pressure
operation and must be replaced immediately af ter
discharging because setting or seat tightness may be
altered. Annually, relief valves must be visually inspected for
corrosion or accumulation of scale and for leaks. Pressure-
relief valves must be removed and replaced with new valves
at least every five years. Even when simply replacing an
existing valve, a review of requirements per current local
and national code is advisable.
NAMEPLATE INFORMATION
The nameplate, located on the side of Hansen pressure-
relief valves, contains important information about the
valve pressure setting, capacity and date of manufacture.
The date code traces the month and year the valve
was built. This is a helpful guide in establishing an
approximate date of service. Example: A valve with Date
Code 0418001 13B, indicates that it was valve number 001
built on April 18 of 2013 to revision level B. See nameplate
below for location of data.
MATERIAL SPECIFICATIONS
Body: Ductile iron, ASTM A395
Piston: Stainless steel
Spring: Stainless steel
Seat Insert: Stainless steel
Seat Discs: Premium grade virgin Teflon
®
(PTFE)
Cap: Steel
Cap O-ring: Neoprene
Maximum Temperature Rating: 240˚F (115˚C)
Safe Working Pressure: 400 psig (28 bar)
Setting Range: 150 to 400 psig (10.4 to 28 bar)
INSTALLATION
Installation should be performed by trained and qualified
personnel only. Hansen pressure-relief valves come with
an installation date tag to identify the number of years the
valve has been in service. The H5600 “R” series capacity
valves have green installation date tags, while all others
are blue. When installing the pressure-relief valve, remove
the knockouts corresponding to the current year and month.
Use a pen to push the knockout partially through the tag
and tear-away from other side.
Pressure-relief valves for ammonia refrigeration are subject
to preventative inspection and maintenance or periodic
replacement Risk Management Program (RMP).
Relief
valves must be replaced after 5 years of service in
application.
However, once a valve discharges it
must
be replaced as soon as possible. Self-reseating is not
dependable because of dirt.
Protect pressure-relief valves from dirt and moisture.
Match capacity on valve nameplate to system document
as specified by system designer and based upon protected
vessel volume. Mount valve directly at the vapor space of
pressure vessel or on connecting non-valved vapor piping
as close to the vessel as possible. Pressure-relief valves
should be installed upright, although horizontal installation
is possible.
Remove plastic shipping cap from outlet of pressure-relief
valve. Connect to vent line piping to protect outlet of valve
from water and debris. Plastic shipping cap will not protect
outlet of valve from falling water or debris. Vent line piping
must have drain line at low point to drain condensate from
line per ASME Boiler and Pressure Vessel Code, Section
VIII, Division 1.
GENERAL PRECAUTIONS
Never expose your face or body to a connected relief valve
exit or piping.
Make sure the valve setting and capacity (see Nameplate
Information Section) meet the requirements per system
design in accordance with local and national regulations.
Be sure to isolate the valve and related piping from the
refrigeration system and pump out pressure to zero before
attempting to install or replace any pressure-relief valve.
Avoid residual refrigerant when doing so.
Remove the shipping caps from both the inlet and outlet
before installation. Install the pressure-relief valve to the
pressure vessel at a location above the liquid refrigerant
level. These valves are for gas relief only. Do not install
shut-off valves in line with pressure-relief valves. Install
valves in locations where they will not be damaged by
moving equipment such as lift trucks, etc. Install valves
in a manner that enables them to be replaced.
1
2
3
6
4
5
MANUFACTURE AND VALVE
MONTH AND DAY OF
INLET AND OUTLET SIZE
AIR CAPACITY ACCORDING
YEAR OF MANUFACTURE
SET PRESSURE
6
5
4
3
CATALOG NUMBER
TO THE SET PRESSURE
1
2
inch
Code:
Date
Capacity
Pressure
Size
..
Set
I n l e t
..
..
Cat. No.
..
O u t l e t
U.S.A.
AND CURRENT REVISION
NUMBER
LETTER
