[modeleng] Re: Balls - what sort do you have and how do you seat them comfortably?

Ye had me worried for 'alf a mo' there, Laddie!

I have always used the traditional method--a SS ball a
short piece of Brass rod and a tap with a hammer, but
you may want to inspect the seat with a strong
magnifying glass to make sure there is not a little
burr or defect in the seat first.  If there is, your
idea of polishing/burnishing may be the best bet.

Al Messer 
--- Peter Sheppard <peter.sheppard@xxxxxxxxxx> wrote:

> No it's not a porn site!
> 
> 
> I have recently been running the Hunslet on air
> (albeit briefly as even 
> with a 50 litre tank it gets through the air at a
> phenomenal rate!)
> 
> One thing I have noticed is that one of the safety
> valves starts to weep at 
> around 30 psi, the other has a far sharper opening
> at 90psi (the loco is 90 
> psi working pressure).
> 
> I have inspected the safety valve and it is a
> "standard" bronze ball on a 
> flat seat arrangement (with a spring to give the
> pressure on the seat.)  It 
> is not a Ross Pop type, but a simple "standard"
> safety valve.
> 
> Obviously I would like it to seat better, so I have
> a number of questions 
> for the esteemed membership of the list!
> 
> 1. What is better - bronze or stainless balls
> 2. Should I reseat by the traditional method of
> stainless steel ball, a rod 
> and a sharp tap; or
> 3. Should I lap a ball into the seat (I silver
> solder a ball to the end of 
> a piece of rod and "burnish the seat) - I don't
> usually use any form of 
> paste, just pressure.
> 
> The seat is about 50mm down in the depths of the
> safety valve, the only 
> access is from the top (you can't separate the seat
> from the chamber).
> 
> Any thoughts, any personal preferences?
> 
> Cheers
> 
> Peter
> 
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