Installation Procedure

PTFE/PFA lined piping systems 

When using smooth-running and greased bolts and nuts we recommend the tightening torques in the table below:

For pressure rating Class 150

DNTorgue (Nm)Screws
1/2”254 x 1/2”
3/4”254 x 1/2”
1″304 x 1/2”
1 ½”604 x 1/2”
2”804 x 5/8”
3”944 x 5/8”
4”708 x 5/8”
6”1308 x 3/4″
8”1808 x 3/4”
10”19012 x 7/8”
12”24012 x 7/8”

For pressure rating Class PN10/16

DNTorgue (Nm) Screws 
15384 x M12
20384 x M12
25384 x M12
32534 x M16
40534 x M16
50684 x M16
65694 x M16
80728 x M16
100758 x M16
1251208 x M16
1501358 x M20
2001728 x M20
25014312 x M20
30017212 x M20
35021012 x M20
40023316 x M24
50024020 x M27
1. Tightening the bolts:
  • Insert the washers
  • Clean and grease bolts
  • Tighten nuts by hand
  • We have taken a friction coefficient of 0.14 (f=0.14) in account.
  • Tighten each bolt using a torque wrench, keeping to the torque values specified in the table.
  • The torque wrench should be used in a cross manner.
  • If a flange connection leaks, despite the fact that all bolts are tight, do not tighten further. Loose the connection, inspect the seal face and re-install.


2. Gaskets

It is a must to use MB-SURELINE®  S58 PTFE gaskets between the flange connection. They are special designed for PTFE/PFA lined piping systems.

All information and data quoted are based upon years of experience in the production and operation of sealing elements. This data may not be used to support any warranty claims. With its publication this latest edition supersedes all previous issues and is subject to change without further notice.


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