4" Burrell Ramsbottom safety valves

I have a near completed LSM design 6NHP 4" Burrel agricultural engine. I am struggling to a point of extreme frustration trying to get a successful workng safety valve. I used the LSM design but I could never get a decent valve seating such that it would hold steam pressure, go off at the 90psi I have chosen to run the engine and of course reset afterwards. I am looking at whether I can purchase a tested safety valve, but I still wish to give this one final go. Looking at the valve towers in the drawing I cannot work out if the seating is flat or at an angle? I am assuming it is flat as per the LSM design. I assume this is phosphur bronze? The valve seatings themselves I assume must be flat too? Is the material stainless steel? The next question is whether these are lapped to seal and if these are lapped in situ or as an individual component. I test the unit on air using a jig I have made, obviously with air thinner than steam there is likely to be some difference after pre set to actual operation. Have you modified the tensioning bolt to enable adjustment whilst in steam. Is this a good idea? I think that is all for now I look forward to any help I can get. Many thanks

The design sounds very like in detail the 4" Foster safety valve, junk that will never work properly as designed.
The seats in the bronze turret want to be flat, the bronze wing valves sealing face wants to be 91* or 92* angle from the wing side with an undercut at the join of wing and seat face so you get a line contact, the wings should be in length at least 2 x the bore of the turret and a reasonable fit in the turret, not to loose to allow tipping or too tight so they jam in use. The wing valves are lapped lightly to their individual bores. The crossbar should have points that sit in dimples in the center top surface of the wing valves that are exactly the same distance apart as the turret bore centers. The dimples need to give the contact as close to or lower if possible than the sealing surface.
If you are visiting Old Warden next week end look me up in the minature section with my Pickfords blue painted Foster as i can show you on paper probably better than on here.

I have not been able to reply until now as a new member. Can I say thanks for the advise you gave me. I made the valves and they work fine. Many thanks again