Induction Heating

Reference: NIA_NGGT0113

Status: Complete

Start Date: Jul 2017

End Date: Mar 2019

Funding Licencee(s): National Grid Gas Transmission

Contact: Kirsty McDermott, .box.GT.innovation@nationalgrid.com

Funding Mechanism Network Innovation Allowance

Research Area: GT - Safety and emergency

Core Technology(ies): Gas Transmission Networks

Estimated Expenditure: £93,600.00

Introduction: Gas flame heating with oxy-propane is the most commonly used methods of applying preheat during in-service welding. Propane by itself does not give a hot enough flame for heating of high pressure gas pipelines, but can be used on low pressure pipelines/pipework. Gas flame heating is relatively cheap in terms of equipment needed, and it is versatile for site use.The disadvantages are:

The welder has to stop working whilst heat is being applied.& bull; There are increased safety considerations due to the naked flame being used in close proximity to other personnel (i.e. welders and inspectors).
Possible overheating may occur which leads to the integrity of the pipe will be comprised and the pipe must be replaced.
Replacing an overheated pipe can cost in the region of £500,000.

Objectives:

To evaluate induction heating techniques to assess the suitability to improve welding process within National Grid.

Expected Benefits: To maintain preheat using induction heating for in-service hot tap welding and include it into business as usual.