Valve Seat Lapping Methods

We are working on a development project for making Valves for process type application. Media to control is DM water, Steamwater mixture.

There are lapped surfaces in side the valve. on ID (Conical) and on surface to surface.

We have a challenge to establish manf and inspection process for :

1) Lapping the Conical Disc seat. Ra = 0.1 (on mean dia 10 mm)

2) Lapping of surface to surface Ra = 0.1 (on dia 15 mm)

3) How to establish method to measure the lapped portions for Id and surface both.

Resources we have : Microscope,

Valve Disc material is ASME SA182 F321 deposited with ASME II SFA 5.21 (Stellite 6)

We have never done such lapping tasks earlier.