HEAT RESISTANT PIPE PURGING SYSTEMS FOR PRE-HEATED PIPE WELDS A wide range of high strength steels containing chromium, vanadium and molybdenum as alloying elements (generally referred to as CMV steels) is prone to cracking during welding. The crack tendency can be reduced by a combination of pre-heat and post-weld heating since this prevents steep temperature excursions and the formation of brittle and undesirable intermetallic phases. The HFT Heat Resistant Pipe Purging Systems have been developed so that pre-heating and welding can be carried out with the purge system in place. Operation The system is connected to an inert gas supply and inserted into the pipe to be welded. The spinal connection hose is long enough for the dams to sit at the outer edge of the pre-heated zone. After positioning the system the argon source is opened, the dams inflated to size and the interspace purged. The purge will remain on during pre-heat and welding. They will withstand temperatures in the region of 300ºC for periods up to 24 hours. The system should be removed prior to post weld heat treatment. Don't use “Home made” devices such as foam or cardboard. Because of the limited flexibility of the heat resisting materials used in construction, the expansion range of each system is +12mm -0mm; each system is manufactured to meet a customer-specified internal pipe diameter. They contain moisture and oxygen. All purging systems are re-usable. Use the proper tool for the job! Use a proper purge system. This puts your weld at risk and leads to costly repairs and delays.

FIVE SIMPLE STEPS FOR PERFECT RESULTS — EVERY TIME For alloy steels an oxygen content below 0.1% is normally considered suitable to ensure that there is no oxidation of the weld. The ARGWELD® Purge Monitor MK V has been specifically designed to measure oxygen content down to 0.1% with a high degree of accuracy. 1 The ARGWELD® Heat Resistant Purging System is positioned using the heat resistant pull tags. (a) MEASURE THE OXYGEN CONTENT OF THE PURGED VOLUME RELIABLY AND ACCURATELY 2 The Heat Resistant Purging System is inflated using the inert gas supply. (b) PurgEye™ 100 WELD PURGE MONITOR™ Before...