Title:

Piping and Valves

Doc. No.

L-001

Annex

F

VSK

Project: NORSOK

Company:

Rev.Date:

 20.09.99

Rev:

3

ID

DATE

VSK. TEXTS

101

20.06.94

Through conduit gate valves:

Valves shall be suitable for installation in any position. (with the exception of stem below horizontal).
Bonnet shall be equipped with a grease fitting for lubrication to stem packing area. Seat skirt option (normally not specified for gass service):
The valve shall have seat skirts enclosing the bore of the gate assembly when valve is in closed position. This is to minimuze ingress of grease which would enter the pipeline when opening the valve. In this case the valve shall be provided with 2 grease fittings in house for body filler, one fitting in top and one in bottom of house.

109

20.06.94

All valves:

All components not specified in the VDS shall have equivalent to or better corrosion resistance than the component they are coupled to. Asbestos containing material is not permitted.

15.12.97

Carbon steel valves and gearboxes shall as a minimum be primed according to NORSOK standard M-501; "Surface protection and protective coating".

20.09.99

Externally exposed components in austenitic stainless steel shall minimum be of type 316 (L) SS.

20.09.99

Fabrication welding of pressure retaining components and attachments welded onto those components shall be carried out according to NORSOK Standard M 601, "Welding and Inspection of Piping Systems". Welding of other valve components shall be carried out according to welding procedure specifications to ASME IX.

20.09.99

Assembly drawing of the valve shall be supplied with the bid, and shall at least show:

• All parts of the valve with material standard and grade, MDS when specified in the VDS and manufacturers part number.
• All welds including hard facing and overlay with reference to applicable welding procedure.
• Overall dimensions.
• Weight.
• Manufacturers name and grade of soft material.

20.09.99

All valves with graphite stem packing, desity of graphite to be 1.3 to 1.7 g/cm3.

110

20.06.94

All valves exept check valves:

The stem or other sliding elements and plugs shall have a hardness and surface finish in order to avoid galling.

112

20.06.94

Ball and gate valve:

The following valves shall be equipped with a drain plug in bottom of the valve body:

155

25.11.94

All valves > = 2":

If drilled an tapped body connections are made (drain, vent, test conn. etc.) they shall be fitted with forged plugs of anti blow out design with hexagon heads. The plugs shall be made to ANSI B 16.14 using same basic material as the body. For austentic materials, the plugs shall be coated to prevent galling. For all carbon steel valves, the body plug shall be of duplex material type UNS S31803. Body tappings shall conform to ANSI B 16.34 or as specified in the valve standard.