Each valve is identified by a unique serial number and all shell and trim materials are traceable to the original material certificate. A reference list of the certificates of the materials used is provided for each valve.

Valves generally comply with ASME B16.34, API 600 and BS 1873.

The stem is a one piece non-rotating design which substantially reduces wear of the gland packing. The depth of the stuffing box is more than twice the travel of the valve from fully open to fully closed. Stem surface finish is better than 0.4 m m Ra and out of roundness does not exceed 0.01 mm. The standard gland packing is PTFE. Graphite is used for higher temperatures.

All internal valve lubricants are chlorine compatible.

1. Hydraulic pressure test of body and bonnet at 1.5 x p_s.
   Acceptance criteria - no visible leakage after two minutes
2. Pneumatic pressure test of backseat usgin nitrogen (oxygen free) at 6 Barg.
   Acceptance criteria - no visible leakage after two minutes
3. Pneumatic pressure test of assembled valve using nitrogen (oxygen free) - body and seat 1.1 x p_s.
   Acceptance criteria - no visible leakage after two minutes.