I'm guessing from a purely insurance perspective that may be the case, but under PSSR anything exceeding 150bar litres (operating Px in bar X Vessel volume) requires a Written Scheme of Examination (WSE) and it will be that Written Scheme of Examination which will specify the inspection frequency and method.
With the scuba cylinders they would hydrostaticly test them in a bath of water as long as the volume before and after testing doesn't change they can go back into service
That’s interesting, how would you measure the volume? Displacement of water?
That indeed they have a tank and a site glass gauge with a floating indicator
thats amazing!!Hi.
Both end caps of the old tank were removed by warming up with oxy-acetylene torch and then a 6ft cheater pipe on a 3/4" drive ratchet. One side shown in the photo must have had it ends cap cross threaded, either at the factory or subsequently when an outlet was threaded into it. It's this end that won't kindly take a new end cap. The old end cap that came off had threads in too poor a condition to reuse.
User: ---not done it yet---
Yes, perhaps you are right. I should have tried copper washers for sealing it up prior to hydraulic testing. The new BSPT fitting I bought for the side with the damaged threads didn't seal, even when done up tightly. Now enough time has passed since I first tried to test it. I'd be willing to go with better seals, and perhaps some kind of tape / liquid seal over the fitting for the bad end.
The photos shown in the first post are after 4 hours tumble cleaning with water, detergent, and pea gravel:
I'm not too happy with the heavy pitting near the drain hole, the pits looks to be half as deep as the receiver is thick. I decided to buy a new one but have only just done so in the last couple weeks. I figured the simplest, least effort, and most reliable way to protect it would be to have it galvanised. It should be among the cheapest methods too if sent in with a load of other stuff. The compressor will be stored in unconditioned space out of the rain so humidity will be high.
This article from a manufacturer of tanks is a good read:
They aren't against it completely and put forward the argument that other parts of the system fail before the tank does.Galvanised Pressure Vessels and Air Receivers – Air Receivers
www.air-receivers.co.uk
As with all things, if you have the money to replace or buy new then save yourself the trouble and do so.
The question of the thread is; has anyone any good reasons not to galvanise a tank?
I may come around to sloshing paint or, more likely, some kind of fuel tank sealing liquid within the new tank, especially along the bottom.
User: --bricol--
Thanks for your message. Yes, considering it sat in a barn for years and had 1/2" saw/brick dust all over the top it's in good nick. The photos prove that the real damage is along the bottom where liquid has been left to sit for years. I'm thinking towards resale value afterwards too. A compressor with a galvanised tank should last indefinately. As for the threads getting bunged up, I've already bought stainless steel fittings and screwed them in with some copper slip to protect the female threads from the zinc.
I found some video footage of during and after, popped them up:
I do like a bit of Galv!
I put off going for a few months on the likelihood of it being rejected. I had some steel pads to galv for a shed build so took it.
