CF flanges are available with tapped or untapped holes. Tapped flanges are available in UNC/UNF or metric threads. Tapped flanges
have through holes, so bolts may protrude slightly from the back of the flange when fastened to an untapped flange. Untapped CF
flanges can be fastened to each other with stainless steel bolts and hex nuts or plate nuts. Plate nuts center themselves over two
adjacent holes and can be held in place with one finger while the bolts are tightened. They are available for most flange sizes from 1 1/3
to 10 inch (33.96-254mm) ODs. As an alternative to hex head bolts, 12-point bolts are available for CF flanges from 2 3/4 to 10 inch
(33.96 to 354mm) ODs. Silver plated bolts eliminate the need for anti-seize compound in clean room environments.
Assembly Instructions for CF Flanges
1. Apply a small amount of high temperature anti-seize compound to the bolt threads.
2. Check that both flange surfaces are clean and sealing edges are free from nicks and scratches.
3. Using clean, lint free gloves, unpack gasket.
4. Place gasket in the knife edge counterbore of nonrotatable flange.
5. Align the mating hole pattern and leak test grooves.
6. Install the proper bolts and tighten hand tight. Check to see that the flange faces are parallel.
7. Tighten the bolts 1/4 to 1/2 turns using a star pattern until the flange faces are metal to metal.
8. Torque the fasteners to the listed value using the same pattern.