A certain number of the tests will have been designated as witness tests. One is usually the hydrostatic test, which does not require an engineer but can be witnessed by an inspector. As a cost-saving measure, if engineers from another project happen to be in the plant at the time of the hydrostatic test, they may be able to arrange to witness the test, because the duration of the test is normally not long. It may take a total of two hours.

If a gas leak test is called for, the test can take place shortly after the hydrotest, especially on the reciprocator cylinder or centrifugal or rotary compressors, where the gas is tested without end seals.

The running tests require time and are generally witnessed by one or more user-engineers. A good team is one design engineer and one maintenance engineer. Of course, more can attend depending on company policy. Agreement on specific test procedures should be reviewed before the test. At times, a performance and mechanical run test may be combined if all conditions for each coincide. More normally, they don't coincide and must be run sequentially. For the additional testing, like string tests and other multiple unit tests, there may be enough delay, because changeovers on the test stand are made, so that it is more economical for the witness to make multiple trips rather than take up an extended residency (see Figures 11-2 and 11-3), The witness must be familiar with the contract, the specifications, and all agreements to properly administer the agreed-upon acceptance criteria. It is counterproductive to have a witness unknowingly approve the test outside the acceptance limits or conversely, to insist on a value more stringent than that for which the contract calls.

A test frequently overlooked is the lube system test. Because of the complexity of separate lube systems and the fact that they may be manu-

Figure 11-2. Changeover on a test stand can be quite time-consuming considering the complexity of the piping and other setup requirements. (Courtesy of Elliott Company}
Figure 11-3. Testing of the more standard integrally geared air compressors can be somewhat complex. (Courtesy of Cooper Turbocompressoi)

faclured at another facility, a separate test is called for. If the timing and logistics permit, the contract lube system can be run with the compressor and driver on the compressor test stand. For any number of reasons, this is normally just not feasible, and a separate test is needed. The witnessed test should carry the same qualifications as required for the compressor.


Once testing and final inspection are complete, the unit is prepared for shipment. The specification should have detailed the type of storage anticipated and expected time. It should have specified indoor, warehouse, outside storage, or whatever is planned. An anticipated time point should also have been stated. The contract should have stated the mode of shipment and destination instructions. Upon notice of shipment, the traffic department (if there is one) may wish to monitor the shipment.

Living Off The Grid

Living Off The Grid

Get All The Support And Guidance You Need To Be A Success At Living Off The Grid. This Book Is One Of The Most Valuable Resources In The World When It Comes To When Living Within The Grid Is Not Making Sense Anymore.

Get My Free Ebook

Post a comment