Problem Summary

Anomaly Description:
An H2S leak was found on the body flange of a 2” Double block and bleed valve, H2S was bypassing the gasket and leaking through the bolt holes.

Root causes:
The root cause of the leak is due to a deteriorated spiral wound gasket and body seal resulting in H2S passing through into the bolt pockets of the valve body.

Integrity concerns:
Further deterioration and complete failure of the 316 stainless spiral wound gasket leading to high amounts of H2S leaking.

  • Line Size: 2″
  • Design Pressure: 75 BAR
  • Operating Pressure: 62 BAR
  • Design Temperature: 156°C
  • Operating Temperature: 156°C
  • Material: ASTM A479 Tp316
  • Line Class: 600

The Beruseal Solution

Clamp Design:
Beruseal designed and manufactured a stainless-steel strongbacking system to contain the system should there be a failure on bolting when drilling into each bolt pocket and injecting a PTFE sealant. Injecting PTFE sealant puts additional strain on bolting where the condition and integrity of are unknown. FEA analysis was performed on the strongback to analyse the stresses in the strongback in the event of total bolting failure on the valve.

Seal:
A successful seal was obtained by drilling into each valve body bolt pocket and PTFE sealant was injected. This repair was successful up until the next scheduled turnaround when the valve was replaced.

  • On-site repairs for maximum up-time productivity
  • Improved Safety by reducing noise & emissions
  • Equipment Integrity with international support & custom engineering

Get in touch with Beruseal