Whenever one-sided welding techniques are used specially in Stainless steel, Chrome or other types of pipes and tubes that require an Oxygen free weld, it is necessary to protect the root side of the weld joint from oxidation.  Protecting the inside of the pipe during welding is called “back purging”.

Flawless welding is only achieved by making sure that oxygen is displaced from the purge zone, prior to and during welding until it cooled down to the point that oxidation no longer can occur. Any residual oxygen can cause porosity, discoloration, weld under bead discontinuities and weekend the joint strength. Welders who follows the direction to use the I purge bladder system to seal the pipe from both sides of the joint and maintain the seal throughout the process, will get the required weld.

The residual level of oxygen in the purge zone needs to be consistent with the welding procedure so continuously monitoring to ensure compliance is crucial.

LNG sites, refineries, power plants, pharmaceutical facilities, food processing, chemical plants and fabricators are doing back purging to get quality weld without redo.


Choose a dependable sealing material  

Preventing oxidation thus avoiding discoloration and weld under-bead discontinuities in tubes and pipes can be achieved by purging the inside with inert gas. Cheapest seldom do the best so examine the options available.

Don’t attract to use sealing discs made from polystyrene foam, wood and cardboard, they may leak or emit contaminants and at worst they catch fire during the hot weld cycle.

Purge Bladder Systems

Aquasol I-Purge Modular Inflatable Purge Bladder Systems are the most effective, innovative and versatile pipe purging system systems available for pipe purging.  I-Purge creates an impermeable seal to consume the least amount of purge gas during pipe purging and welding, system not only save time and money but also achieve consistent high-quality welds.

This system is specifically designed to be easily pulled into position through long sections of pipe and around elbows without the risk of getting jammed or stuck in the pipe. After cooling down the weld zone area turned off the gas and deflate the bladders so the system can be pulled out through the pipe for the next weld.

I-Purge design has become standard and surpasses existing technology with its advanced design.

  • It provides the complete solution for all pipe purging needs for pipe welding under Inert gas.
  • Volume of gas used to purge is minimized, resulting in significant savings in both time and the quantity of gas used.
  • Return on investment can be achieved in as little as just in few welds.
  • These robust systems can be used over and over again paying for themselves in very little time.
  • These systems are the fastest method of pipe purging with no time wasted building, taping or gluing dams in place, and no time wasted purging long sections of pipe.
  • Due to their superior design, the purge time required is up to 8 times faster than foam, cardboard, plywood or other conventional purging methods.

Whatever system is selected ensure that the inert gas enters slowly. Argon as compare to air is heavier so introduce it slowly and discharge from the highest point. If welder uses Helium as purging gas which is lighter than air so it is inserted from the top of a cavity, gases are then removed from the base, use PRO OX 100 to monitor the oxygen level inside the cavity to start the welding.



The I-Purge comes equipped with several advanced features such as its Quick Connect Fittings that allow easy assembly and disassembly of components.

The I-Purge can also use extended harness length for the bladders to be placed outside the heat affected zone. Components used in I-Purge, made from heat resistant materials that are stable and thermally resistant and non-toxic.


  • Internal hose and protective external fiberglass sleeve capable of withstanding high temperatures
  • Flexible harness easily pass through pipes, including elbows and tees over 90°
  • Equipped with glowing indicator to align the I Purge system at root gap for perfect joint.
  • Various lengths of harnesses are available to accommodate heat affected zone during preheating and high heat applications.
  • Corrosion resistant proven lock mechanism for secure connection

Pull Loops

  • I Purge must be deflated completely before it is pull into or remove from the pipe, a rope or chain can easily be connected with I purge.
  • Moderate tension (approx. 5 lbs.) should be applied on pull-wires to prevent sagging of the harness during installation and operation.
  • Bladders must be deflated, extracted, cleaned and stored in the provided carrying bag, that protects the bladder from dust and debris for prolonging life


I-Purge Isolator & Single Purge Bladder

The I-Purge Isolator is designed to function as Purging as well as non-purging applications. Pipe system sealing for servicing, cleaning and inspection, including purging of valves or tanks

Unlike other models with permanent fittings, a pipe reducer can easily be created by simply connecting two bladders of dissimilar sizes to create unique pipe configurations

Bladders are available in sizes ranging from 2 to 48″ purchased either individually or as a complete system. Ideal for petrochemical plants, LNG plants and fabrication shops.

Aquasol I-Purge system surpasses existing technology and an edge over the other competitors with its advanced design, quality and provides the complete solution for all pipe purging needs.

Metal Welding is the sole distributor of Aquasol products in Pakistan and if you are in other part of the world even though can contact us for information or quotation through email. All the supplies will come directly from Aquasol by courier to your door step.