Making Sure Steam Piping Is Safe - the role of welders

Over at Parmaceutical Processing magazine, they've got a good article about keeping steam piping safe. Lots of welding tips in it - check it out. They call it "10 simple things that might keep you alive."

Some good snippets:

It is very important that you understand what you are looking at and the consequences of being wrong when it comes to evaluating piping systems. Let’s start with the pipe itself. Most pipe you will ever encounter starts its life at a steel mill in sheet form. In many cases, the mill rolls the sheet into tubes and welds it...

Pipe gets assembled to other pipe, fittings, and flanges by either welding or threading. There are specific code requirements that describe when it is permissible to thread or when welding must be used. Within the welding world, you also need to be aware of several other possibilities. Flanges and fittings come as either slip on or weld neck. Slip on fittings are just that, slipped onto the end of the pipe. The flange is then welded up around the contact points on the inside and outside of the pipe and the flange. Slip on flanges are not considered as strong a joint as weld neck or butt welded connections...

Welding on pipe, fittings, flanges, and pressure vessels must only be done by someone with the proper credentials. Welding on pressure piping must be performed following qualified welding procedure specifications. It is the responsibility of the installer to have welding procedure specifications that are certified to meet the applicable ASME code construction;(refer to ASME code Section I and B 31.1 and ASME Code Section IX for welding procedure specifications). The National Board Inspection code which is required for repairs of pressure equipment also includes AWS (American Welding Society, www.aws.org) standard welding procedures. Every detail of AWS standard welding procedures must be followed when welding or the weld can be deemed to not be a qualified weld and in jeopardy of having to be removed...

Welders must also be qualified to the requirements of ASME code Section IX. Once qualified and certified, the welder can only weld within the variables listed on their welder’s performance qualification record. The welder must also weld within the process at least once every 6 months or the qualification expires. Records must be kept to prove that the welder had welded at least once every 6 months. Welders will mark their welds with stamping to identify which person welded which joint. This stamping could be there on your system but possibly obscured with insulation...