different types of safety valve and its various part function

Draw the drawing of safety valve and some question on it
Ans.

Lip Clearance- The purpose of the lip clearance is to make sure that your v/v lid completely sit on the seat or not if lip clearance become zero then v/v will not able to seal properly or it will not close completely

Blow Down Ring - The purpose of the blow down ring is to make sure that boiler will not act like the relief valve means when boiler lift up at 10 bar example then at the time when v/v lid sit back on the
seat pressure should be 9.5 bar so with this we set the blow down pressure if setting is too high then we loose excess stem and if set too low then chattering effect willI be there.

Compression Nut-It is used to set the pressure at which safety v/v should lift.

Split Collar- It is used so that no one should change opening pressure setting of the safety valve

Floating Ring-In previous type of safety valve we don't have floating ring so after the long term of use exhaust stem piston stuck and safety v/v pressure setting will be affected so that was the reason
we use floating ring so that exhaust steam piston move freely with the help of floating ring.

Easing Gear-The purpose of easing gear Is to make sure that all the part are lifted properly means It was not stuck inside the safety valve.

What are the different types of safety v/v and how much the lift should be there so that accumulation of pressure should not be above reasonable/acceptable limits.

Ans - Three types of safety v/v are there
1. Ordinary safety v/v- they do not have exhaust steam piston and no floating ring but it have
wings. Lift of this type of valve is D/6
2. High lift safety valve-Valve with wings and exhaust steam piston but no floating ring. Lift or
this type of valve is D/24
3. Improved high lift safety valve - No wing, but it contaln exhaust steam piston with floating ring. Lift of this type of valve is  D/12

Required Lift so that accumulation pressure should not be there is-
Ple/4 DxD=Pie x DxL

L=D/4
Where L= Lift
D= Diameter of the v/v lid
Note-Floating ring is the loose ring so that when exhaust steam plston lift up, the floating ring will lift up along with the piston.