Pressure Vessel Modification and Repair

Oftentimes, it is less expensive to alter or repair existing equipment rather than incur capital expenses from fabricating new.  Weld failures wreak havoc within production lines and may be detrimental to the overall business.  Certified under ASME, we provide a wide range of pressure vessel modification and repair services, including: modify or repair a port that is already in service, add or remove a port, add a manway, repair jacket leaks, cracked welds, excessive pitting, adding a mag mixer, removing an old mag mixer and replacing with new (changing model or brand).

R Stamp Certified

Sometimes new processes require alterations to existing vessels. It is important to note that any weld repairs to the ASME pressures zones on tanks, require an R-Stamp. The R-Stamp is a certification required by the National Board of Boiler and Pressure Vessels for repair of an ASME tank or vessel. It’s a strict set of quality and safety guidelines pertaining to the repair of critical zones on boilers, pressure vessels, and any pressure-retaining component that requires weld repairs that will retain an airtight seal for years to come. For example, pressure tanks that contain flammable or hazardous chemicals require the utmost in precision welding to ensure that the potentially deadly gasses stay trapped safely inside.

With an “R” certification from the National Board of Boiler and Pressure Vessel Inspectors, Allegheny Surface Technology is able to provide repairs and alterations to pressure vessels and pressure-retaining items fabricated to ASME specifications as well as other specifications.

Pressure Vessel Repair Capabilities

  • ASME R stamp
  • ASME code welding
  • Add or modify ports
  • Replace bottom valves
  • Reinforcement pads
  • Repair mag mixer
  • Confined space entry
Service Description Benefits Application Scenarios
Welding An activity that is used for binding materials together through the application of heat.
  • Establishes strong, durable, and permanent joint links
Crack repairs, port removals, port additions, sight glass additions, tank alterations, or filling pits.
Pressure Vessel/Tank Weld Repairs Pressure rated vessels require a Code Certified welder that works for a company that holds an “R” stamp. A pressure vessel is a tank or vessel that has been designed to operate at pressures above 15 p.s.i.g (Registered with a National Board) or greater.
  • Restores a vessel to its original and intended operating condition
  • Allows for safe operation
  • Prolongs the vessel's life
A pressure rated vessel that would require any type of weld repair. Common issues include cracked weld, tank modifications, or excessive pitting.
Quality Inspections/Pressure Testing Test to ensure the operating pressure of a tank/vessel meets requirements. A pressure vessel is a tank or vessel that has been designed to operate at pressures above 15 p.s.i.g. or greater that must be welded to code, R-stamped and inspected by a third party AI (authorized inspector), which we provide.
  • Critical to maintaining operations and people's safety
Replace a mag mixer base/weld plate, repair a cracked weld, weld repair a leaking jacket or perform any modification/alterations to a pressure rated tank/vessel. This must be done before applying a Repair tag (“R” stamped tag) to the equipment after the pressure test has been witnessed by a third party Authorized Inspector (AI).

Alterations to a Pressure Vessel

Pressure vessels are containers designed to hold liquids, vapors, or gases at high pressures, usually above 15 psig.

Alterations to a pressure vessel are often required to accommodate changes in process design (i.e. installation of new nozzles in the vessel shell). Occasionally, internal components must also be modified for new process designs. Access to a vessel within a process may be obstructed by adjacent equipment, resulting in restricted access for tools and equipment. Repairs of this nature will normally require more time than if performed with a standalone vessel. Plans should be made well in advance of the scheduled shutdown to make certain that the repair organization has time and manpower available to complete the repairs on schedule.

The National Board Inspection Code requires a repair organization to have an ASME Certificate of Authorization to cover the scope of the repair or the alteration. It is recommended that only organizations holding an ASME Certificate of Authorization perform these repairs. The requirements for the alteration of pressure vessels concerning materials, replacement parts, welding, post weld heat treatment, and inspection are identical to those for repairs.

The National Board Inspection Code also requires the acceptance of repairs to a pressure vessel by the authorized inspector before the vessel is reintroduced into service. The authorized inspector will usually require all the nondestructive examinations (NDE) for the repair that were required by the ASME Code during the original construction. All repair welds to vessels should be subjected to virtually full coverage NDE, considering the process conditions the repairs must withstand compared to the vessel integrity at the time of fabrication.


What Our Customers Are Saying