Monday, 27 June 2011

Sentinel 7109's Superheater passes 550psi Hydraulic test

After repairs, a boiler has to pass an initial hydraulic test (water) at 1.5 times working pressure to ensure that it is physically sound. The superheater, because it works at a higher temperature to produce dry steam, has to pass its initial hydraulic test at 2 times working pressure. For a Sentinel, this means 550 psi (~38 bar).

I'd thought that the hydraulic test would require some pretty sophisticated equipment; however, this is not the case.

First the far end of the tubes need to be blocked. The sealed ends can be slackened to let air out so that there is only incompressible water contained.

Blocked superheater tube-ends
Then an artistic arrangement of pipework is attached at the near end (the bicycle wheel is not essential).
Artistic pipework
The hydraulic pump is then connected to the artistic pipework and pressure applied.
Check the gauge reading...
...this one's easier to read.
About 565 psi (39 bar)
So how is the pressure applied, I hear you ask? (Note the video was shot by the owner). Starring Justin & Pete.

(Any suggestions for the owner to do the hard work are met fiercely by the camera lens!). Clearer video on YouTube.

The pressure has to be held for at least 30 minutes. If satisfactory, then the test is deemed passed and a certificate written on the spot and issued.
Al fresco computing
Many thanks to Justin Goold of J R Goold Vintage Steam Restorations Ltd and Peter Hawkins of Hawkins Inspection Services Ltd for their services.

1 comment:

  1. Congrats, Andy, another milestone passed. Looking forward to seeing her in steam for the SC/DC 150 celebrations next year. JW


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