Order this important seat leakage set and save on FCI 70-2-2006 and 70-3-2004 FCI 70-2-2006: This standard establishes six classes of seat leakage for control valves. Also defined are specific test procedures to determine the appropriate class. Included are classes commonly associated with double-port, double-seat or balanced single-port control valves with a piston ring seal or metal-to-metal seats; commercial unbalanced single-port, single-seat and balanced single-port valves with extra tight piston rings or other sealing means and metal-to-metal seats; valves for critical applications where the control valve may be required to be closed, without a blocking valve, for long period of time; and resilient seating control valves with "O" rings or similar gapless seals, among others. FCI 70-3-2004: This standard applies to pilot operated and direct acting pressure reducing, pressure relieving (back pressure), differential pressure and temperature regulators.Selection of a leakage class is not restricted as to regulator design, but acceptable values for various commercially available designs are suggested for each class under Section 4.The standard cannot be used as a basis for predicting leakage at conditions other than those specified.This standard is similar to FCI 70-2.This standard does not apply to pressure regulators as defined in the following standards: - ANSI Z21.18/CSA 6.3 - ANSI Z21.80/CSA 6.22 - ANSI Z21.78/CSA 6.20