Cheddar Hercules Pressure gauge thread size

[Midwalesstokie]

The pressure gauge on my Hercules has broken so I need a new one. Does anyone know what size the thread is on the pressure gauge or how I can measure it?
The measurements of threads I've seen aren't metric so I've got no idea how I measure them, 3/16 seems a popular size, is this right?

 

[David BaileyK27]

Re:Cheddar Hercules Pressure gauge thread size

Most of our small presure gauges are threaded 3/16" x 49 ME thread.
David Bailey http://www.djbengineering.co.uk/ < Link To www.djbengineering.co.uk

 

[David BaileyK27]

Re:Cheddar Hercules Pressure gauge thread size

Sorry that should have been 40 ME, jusy a slip of the finger.
David Bailey

 

[Midwalesstokie]

Re:Cheddar Hercules Pressure gauge thread size

Thanks David. Any idea how I measure the thread?

 

[minimans]

Re:Cheddar Hercules Pressure gauge thread size

Thanks David. Any idea how I measure the thread?

Best way to measure thread forms and pich is with a gauge like these..............

 

[Midwalesstokie]

Re:Cheddar Hercules Pressure gauge thread size

I've seen them for sale in shops and always wondered what they are for. I'll have to try and get a set.

 

[steveciambrone]

Re:Cheddar Hercules Pressure gauge thread size

These are the best ones i have bought. Through hole for diameter sizing and threaded holes to determine thread sizing. Not cheap but then most good tools are not.

Steve

 

[Elmtree Line]

Re:Cheddar Hercules Pressure gauge thread size

From what i can see the gauge and connections are identical to Roundhouse ones, so a quick phone call to Roundhouse might help as they may be able to sell you one.

 

[tagorton]

Re:Cheddar Hercules Pressure gauge thread size

These are the best ones i have bought. Through hole for diameter sizing and threaded holes to determine thread sizing. Not cheap but then most good tools are not.

Steve

They might. It also might be cheaper elsewhere. http://www.steamfittings.co.uk/asp/...e with siphon so just remove old and bolt on.

 

[Midwalesstokie]

Re:Cheddar Hercules Pressure gauge thread size

Thanks for all the replies everyone. I went for the simple option and tried fitting any of the other pressure gauges I had. It turns out the Roundhouse gauges fit so I've ordered one of them.

Incidentally, I think it was the cold that damaged the gauge. The locos are kept in the house in the Winter but were left outside in the shed which gets very cold ,after a running session. Hercules works fine as i've steamed it since with a Roundhouse gauge but the original gauge won't go below 20psi. Can this be repaired or is it just a replacement job?