Evoqua Wallace&Tiernan 50-200 Series, Manual

Page: 59 / 111

WT.050.200.001.UA.IM.0814
50-200 EVAPORATOR FOR CHLORINE
48
EVOQUA W3T98237
4.14.1 Evaporator Gas Pressure Relief System
a. Carefully remove the rupture disc. Do not damage the surfaces or the
remove tape that secures the components together. Check the system
components for signs of internal or external corrosion. Replace as neces-
sary.
b. Reassemble safety head (union) without the rupture disc.
c. Pressurize the system at rupture disc connection to 50 psi with dry air,
carbon dioxide, or nitrogen. Alarm should activate imediately and pressure
should hold. Check for leaks.
d. Reinstall the rupture disc and pressurize to 150 psi. Pressure should hold.
If an alarm sounds or pressure does not hold, replace the disc and retest
at 150 psi.
4.14.2 Liquid Line Pressure Relief System
a. Loosen the union nut on the union safety head. This will separate the union
halves and allow you to lift off the expansion chamber (11) and pressure
switch (5) as an assembly. This will also give you access to the rupture disc
(10). Refer to Dwg. 50.202.007.011.
b. Carefully remove rupture disc. If any internal or external corrosion is
noted, the expansion chamber must be hydrostatically tested at 840
psig (and cleaned and dried) or replaced. Replace other components as
necessary.
c. Reassemble the safety head (union) wihout the rupture disc.
d. Pressurize the system to 50 psi with dry air, carbon dioxide, or nitrogen. An
alarm should activate immediately and the pressure should hold. Check
for leaks.
e. Reinstall the rupture disc and pressurize to 150 psi. Pressure should hold.
If an alarm sounds or pressure does not hold, replace the disc and retest
at 150 psi.
4.14.3 Pressure Alarm Switch
If an alarm does not activate during the relief system test, perform the checks
detailed in paragraph 4.4, Relief System Pressure Switches, to determine
whether the switch requires adjustment or replacement.