You really must speak to your club boiler inspector. He should be seeing your boiler in stages through its construction so that he has confidence in your workmanship.

The working pressure for your boiler will be on the drawing or in the "words & music". If not then your inspector will be able to advise how to determine the permissible WP from the drawings.

Assuming you are in the UK then the test requirements for copper boilers as agreed with the HSE and published by the various associations are:

The initial hydraulic test without fittings will be to twice working pressure taken up in stages and held for at least ten minutes.

Subsequent hydraulic tests with fittings in place are at four year intevals to 1.5 x WP.

An annual visual examination is required together with a steam test to prove the safety valves will not allow the pressure to exceed WP plus 10% and that the pressure guage is accurate and that the boiler has two independent means of being supplied with water.

The pressure guage must have a range of at least WP plus 30%.

A copy of the relevant document is available from http://www.southernfed.co.uk/ although many clubs have the information on their website.

I'm pleased to see you are building your boiler yourself, but I stress that it must be done properly and tested in accordance with the requirements otherwise you will be wasting your time and money.

Eddie