clack valves

Hi guys got a problem with my inline clack valves.

they are not sealing can hear bubbling in tender plus steam always coming back through both injectors.

i have took them both of cleaned in citric acid first then tapped the ball to make sure the seat is ok.

blowing down seems to seal but hot water still going back into tender.

The clacks are new from Polly and fitted horizontal cant see why with the pressure of the boiler why they don't work.

are their different types of clacks my feeds go on the top of the boiler hence why i used horizontal clacks any ideas please

Hi Ron,

Have you tried replacing the balls, they may not be perfectly round.

Sometimes they can get damaged when they are hit to form a seat and it is good practice is to replace them with new balls.

Paul.

Hi Paul yes I have ordered new stainless balls just in case. They look fine but think safer to fit new ones. The strange part is it's leaking the same as it was before cleaning and seating balls. More strange as both are brand new.Ron

Hi Ron,

You have said that your clacks are in the horizontal position. It is worth checking if they work better when vertical. This should not be a problem but worth investigating.

Paul

They have to be horizontal for them to work. Their is no Spring it's just the pressure in the boiler that keeps them closed.

Ron

Have you tried Viton / nitrile balls.

Mick

No I ordered stainless balls

Ron

The standard method to form the seat, was to use a standard hardened steel ball (obviously of the same diameter) first and not the soft stainless steel ones.

Save the stainless steel (or bronze) balls for use in service.

Nick.

Edited By Nick Hughes on 21/06/2016 10:07:04

Hi Guys took Clacks back to Polly so they could check them for me they found both leaking at 40 psi they had one in stock changed that and sending the other in about 3 weeks when new stock arrives'

Fingers crossed now hoping soon be running.

Ron

Well the replacement clack valve from Polly was also faulty seems like they had a bad batch.

Been waiting weeks for replacements. still waiting so frustrating waiting so long was so surprised they did not have the facility to re seat the bottom of clack.

Been in touch again today and they are still waiting for stock.

The time trying to solve problem then after trying to get the new ones has really surprised me.

Most of summer nearly gone and still not been able to use my Loco.

trouble is now loosing interest after so many problems think i should have maybe took up another Hobby.

Fingers crossed soon be here

Ron Hancock

Hang in there Ron! Some people spend 40 years building a loco than never get round to steaming it. At least you are on the home straight now.

Neil

Ron, I think I would re-face the seat with a 'D' drill bit and make the seat again with the same size (or a tad larger ) steel ball. Then use your stainless ones. To leak at 40 psi doesn't say much for the manufacturer and perhaps Polly are caught in between. I would have thought Polly would have re-seated them for you as an act of faith - after all, they are trying to encourage model engineers. Our Polly rep in France is most obliging.

BobH

Well Neil bit of good news a friend had spare 1\4 clack same as mine just filled boiler 3\4 full put a fire in her she soon got to 90 and no leaks.

i just need to try it with tender on make sure the injectors work and might be ready to try it.

surprised how things can change with just a little luck.

yes i feel Polly have been let down by their supplier cant fault how they immediately checked them and said they would replace them just the amount of weeks waiting for new ones