General Purpose Pressure Vessels
w w w . p a r r i n s t . c o m
11
9. Routinely inspect the bolts on split ring clo-
sures for lubrication and cleanliness. These
screws should not be allowed to dry because
the threads will seize. Regularly apply Parr High
Temperature Anti-Seize Lubricant before this
happens. It is important to keep the bolts lubri-
cated so they will not seize and also to achieve
the intended torque value.
10. Routinely inspect screw cap threads for wear
and cleanliness.
11. If servicing assistance is needed, contact Parr In-
strument Company direct at the address shown
on the back of these instructions.
Periodic Pressure Tests
Each cylinder used in a Parr pressure vessel is tested
under hydrostatic pressure to the higher of 1.43
times the rated working pressure at room tem-
perature or 1.30 times the rated working pressure
corrected for temperature before it is released from
the factory. Micrometer caliper measurements are
taken during this test to check the deflection of the
walls under pressure. Excessive deflection or failure
of the metal to resume its original dimensions after
pressure is released indicates that a cylinder is po-
tentially unsafe and it will be rejected. Similar tests
should be made at regular intervals during the life
of each cylinder, and particularly whenever the user
suspects that the equipment has been over-stressed
or damaged.
Some laboratories maintain hydraulic test facilities
and make it a rule that all pressure vessels must
be tested at regular intervals. Records are kept of
deflections at specific test pressures so that any
increase in deflection becomes a warning that the
metal has lost strength. Any cylinder that fails to
return to its original dimensions after application of
the prescribed hydrostatic test should be discarded
as unsafe for further use.
Users who do not have pressure test facilities can
return any Parr pressure vessel to the factory for hy-
drostatic testing and overhaul. This should be done
whenever the metal shows excessive damage from
corrosion or whenever an over-pressure or other
unusual occurrence raises any safety questions.
To return a vessel for repair, contact Parr Instrument
Company for a return authorization number (RMA).
Apparatus returned for testing and overhaul should
be shipped prepaid to the following address:
Ship repair to:
Parr Instrument Company
Attn: Service Department
RMA # XXXXXX
211 53rd Street
Moline, Illinois 61265
USA
An order or letter of instructions should be mailed to
the same address, as no repair work will be started
without specific instructions and a Health & Safety
Assurance Certification form (FX004) signed by a
responsible user.