For proper functioning of metal seals following guidelines are to be followed.
Flange
Make sure the flanges are turned and not milled. The turning operation will create a circular pattern which is good for sealing.
In case of elliptical / square seals, the milled groove needs to be properly polished to remove the circular pattern created in the groove by the cutter.
Make sure the flanges have enough holes for proper clamping of seals.
Make sure the bolt sizes are sturdy enough to create the seating load on the seals.
Make sure the flanges are rigid enough to avoid bending.
Make sure the seal is as close as possible to the bolting position.
Check if the Ra value of the flanges is 0.4 um.
Grooves should be scratch free.
Seal
Make sure the seal packet is opened at the time of installation only.
Once the seal is out of the packing, make sure it directly goes in the groove.
No surface scratches on the seal surface permitted.
Make sure the groove is free from oil and other unwanted particles which will affect the seal performance.
In case of high leak tightness requirement, one should use hand gloves.
Make sure the seal is not in contact with any sharp object.
Installation
Before installing the seal, the groove should be cleaned properly with a dust-free cloth. One can use acetone or isopropyl alcohol for a dust-free groove.
Avoid scratches on the seal as well as grooves.
Install the top flange on the seal avoiding rubbing on the seal surface.
Tighten the bolts crosswise to create a uniform seating load on the seal.
Do not use sharp objects to place or remove the seals.
Open the seal packing only at the time of installation.
Use hands for installation and avoid metal parts for handling.
