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How to install repair capsules in Series 151 steam traps
YARWAY
PROCESS THERMOSTATIC STEAM TRAPS
SerieS 151
OPERATION
Series 151 steam traps are designed for use
in process heat exchange applications. A filled
thermal element actuates the pilot valve. The
main valve/cage assembly is actuated by fluid
dynamics. Discharge is basically cyclic in
nature and occurs near steam temperature.
The pilot valve can discharge condensate
continuously, but will close when dry steam
reaches the trap.
WARNING
Hot discharge from this product may cause severe
burns. Discharge must be piped away or directed
so that persons in the vicinity are not endangered.
This product must be isolated, vented and cool to
the touch before repairing or inspecting.
VCIOM-05067-EN 17/01
INSTALLATION
Before installing the trap, blow out the piping
thoroughly to remove loose scale and dirt. Use
pipe dope or tape sparingly when attaching the
trap to the pipe.
Observe the pressure limitations and flow
direction shown on the trap label. Install the
trap in an accessible location for inspection
and maintenance, below the equipment being
drained (see Fig. 1).
STRAINER
Series 151 traps have built-in screen. Install a
separate Yarway series 921 Wye strainer with
blowdown valve.
FIgURE 1
Recommended installation
Full pipe size of
equipment outlet
¾” Min. for 151
1” Min for 151H
Isolated valves
(gate or Ball)
Test valve
(gate or Ball)
Union
Series 151 - A trap
921 Strainer
20" min
Series 151-A (Angle) Series 151-I (In-Line)
SPECIFICATION
ANSI Class 300
Maximum Operating Pressure: 300 psig (21 bar)
Maximum Operating Temperature: 500F (260C)
Minimum differential: 1 psi (.07 bar)
Maximum test pressure: 740 psig (51 bar)
Nominal Capacity
100 psi (7 bar) near saturation temperature.
Series 151: 4500 lb/hr (2040 kg/hr).
Series 151H: 8500 lb/hr (3850 kg/hr).
End Connections
¾”, 1” NPT-ANSI B1.20.1
¾”, 1” Socketwelding-ANSI B16.11
Position
The trap may be installed as shown in Fig. 1
with discharge downward or with bonnet on the
side. For freezeproof installation, it should be
positioned vertically or on its side. Make certain
that the arrow on the body agrees with the
direction of flow.
Discharge piping
To avoid excessive back pressures, discharge
piping should be amply sized. For short
discharge lines, (up to equivalent length of 10
ft.) use pipe equal to trap size. If several traps
discharge to a common return line or manifold,
size the line to prevent buildup of excessive
back pressure during the simultaneous
discharge of all traps. All piping and fittings
downstream of 151H traps must be 1” or
larger.
