repair work on 8" CL 1500 bolted bonnet Globe valve 1

[Valveusa]

Hi . I am doing some repair work on 8" CL 1500 bolted bonnet Globe valve. The sealing surface HF seat ring and disk 410SS. The sealing surface( Cup type) height is about 1/2". lapped with 180 grit size .It failing pressure at 1000 psi.
What option we should take:
[li][/li]Use hemmer type Gear Bigger.
[li][/li] Lap with higher grit size lapping compound
[li][/li]Change height for sealing surface
Any Idea?
AL

 

[gerhardl]

Any way to test-check possible leakages with demounted top and globe weghted down to seat sealing and observe (soap water?) at lower (non dangerous) pressure to find out if leakages are consentrated to one or more places or all over, or non-existent at low pressure?

(Good sealing at low closing force is more difficult to obtain than at higher torque)

Positioning parts (bonnet flanges, sealings,yokes, threads, bosses) giving correct, non-skew, even pressure and positioning of the two sealing surfaces?