With 7903 securely locked away in the shed and most of us not doing much steam work we thought we would try and catch up on some outstanding jobs. The two Snifting valves, correct title is anti-vacuum valves valves currently fitted to our engine are ex BR valves and over a period of time the valve inside and its sealing seat have worn to the maximum tolerances and therefore pass steam. They were bought I believe from Swindon works in the very early days of our parts procurement during restoration. They are in fact the later BR designed ones as fitted to the BR Standards. What we have done during this period of lockdown is now make two brand new valves to the correct design with new stainless steel valves inside. The stainless steel valves and the Body castings have been in our possession for some while so Covid 19 is not all bad news John Hancock has had chance to machine up the complete new valves.
Depending how long this difficult situation stays with us we have the refurbishment of the Cylinder Relief valves next on the list. These again were made with a mixture of old and new parts on the original Restoration. We have brand new valves and the correct section springs in stock so John will give them the John Hancock treatment.
Update
We start work on preparing 7903 for a return to service when we will refill the boiler with water and carryout a mechanical exam as well as finish some rear spring adjustment.
We are also fitting the two brand new snifting valves, mentioned above see pictures on Home page. These are the two valves that sit on the side of the steam pipes going from the top of the cylinders into the side of the smokebox.