Parr Instrument Series 4558 - Manual (Page 23)

4555 - 58 Series
5G & 10L Pressure Reactors
- 22 -
PERIODIC PRESSURE TESTS
Each cylinder used in a Parr stirred reactor is tested under hydrostatic pressure to 1.3
times its maximum rating before it is released from the factory. Micrometer caliper
measurements are taken during this test to check the deflection of the cylinder walls under
pressure. Excessive deflection or failure of the metal to resume its original dimension after
pressure is released indicates that a cylinder is potentially 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 which 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 hydrostatic 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. Apparatus returned for testing and
overhaul should be shipped prepaid to the Parr Instrument Company, 211-53rd Street,
Moline, Illinois 61265. 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 (F0042) signed by a responsible user.