DWI Approval 31.4.a for Steel FittingsPosted on Dec 09, 2015
Lortub, a supply partner of FT Pipeline Systems, is the only supplier to have DWI 31.4.a approval in the UK market for its steel fittings lined with high performance Eurokote 468 Thixo.
Fittings are always a point of debate when it comes to DWI requirements and if suitability under 31.4.b (contact times and surface area to volume ratio) is sufficient. However, it is the opinion of FT Pipeline Systems that large diameter mains such as those being considered in the UK at the moment, should have DWI 31.4.a approved fittings as well as mainline pipe.
The Lortub E Joint, lined with Eurokote 468 Thixo was recently cyclically tested a number of times to 40+ bar. A further test was then applied to the E Joint – that of a sub-atmosphere test to look into the effects of a near vacuum on the lining product.
With all the tests performed there were no detrimental effects observed to the internal lining.