Premium PWHT Services Perkongsian Liabiliti Terhad [202004001391 (LLP0024167-LGN] was incorporated as a wholly-owned Malaysian heat treatment company, specializing in offering Pre-heating, Post Weld Heat Treatment in-situ services to the Oil & Gas, Petrochemical, Power Generation, Marine, Metal Fabrication and Metallurgical industries. We also provide both electrical and gas-fired for dryout/curing of refractory linings.
The management and field staff of the company consists of Malaysian individuals highly trained on the practices and applications of heat treatment as well as being very experienced in the practical methods of conducting heat treatment in accordance with Engineering Codes and specifications. Our edge in the industry is in our dedication to ensuring the technical services offered are of highly efficient and professional standards.
The management and staff consist of personnel that have significant ‘hands-on experience in the planning, coordination and successful execution of projects large and small in Peninsular and East Malaysia, as well as in neighbouring countries.
Premium PWHT Services offers a wide range of heat treatment services involving electrical resistance, localized Pre-heating and Post Weld Heat Treatment Services. These include on-site preheat and post-weld heat treatment of pipe butt welds, welding seams on pressure vessels and storage tanks, inclusive of other weldments, forgings and castings. The heat treatment works are carried out utilizing our 50kVA transformer units. This equipment is unique as a standard unit comes complete with a built-in semi-automatic programmer and a stand-alone 12pt. temperature recorder. This effectively turns the unit into a self-contained workstation that is not only robust for site conditions but also versatile for efficiency. Each unit is capable of powering up to a maximum of 18 x 60V rating ceramic pad heaters, giving it optimum production capacity. These transformers provide a safe power output of up to 80V ratings. The connections of the secondary double looped power cables to each heater are by brass camlock connections protected by insulation sleeves to meet industrial safety requirements. The equipment and heaters are designed to comply with the requirements of governing engineering codes and heat treatment specifications such as BS, ASME, ANSI, etc.
Flexible Ceramic Pad (FCP) Heaters
Design & Detail Engineering (Marine, Piping, Structural,
Hull & Appurtenances)
Low voltage (60V) heating elements designed from ceramic beads are utilized to heat up components within governing specifications. These elements are robust and versatile, which are best suited for these applications as they come in a wide range of configurations and sizes according to the requirements of the job. The installation process for these heating elements is both simple and quick which are vital to the efficiency of the heat treatment production on site. An added advantage provided by this method is the provision to revamp damaged heating elements on site. This eliminates costly turnaround time to circulate heaters back into production on a site with work still in progress. Each element has an optimum working temperature capacity of up to 850°C to 900°C. For safe and quick installation, each heating element comes complete with insulated brass camlock connectors. As for preheating works, specially designed flexible pre-insulated (FIP) heating elements are utilized. They come completely encased in a stainless steel mesh and protected by a stainless steel backed plate that is insulated with ceramic fibre for a fast and efficient installation process. These heating elements are capable of heating the workpiece up to 350°C. At areas that are awkward for installation, special coupled rectangular or round magnets are utilized to hold these preheating elements firmly in place.
Heat treatment is conducted by placing the component into a thermally insulated furnace. Radiant heating through atmospheric heat transfer is affected by the placement of high-velocity gas burners fired directly into the furnace atmosphere. The specially designed burners create a ‘scrubbing action’ of hot gases against the external walls of the component placed in the furnace. The burners produce clean combustion with no contaminating by-products. Combined with a positive internal pressure created by these burners into the furnace, detrimental hot and cold spots are effectively eliminated through proper heat distribution, thereby achieving temperature uniformity throughout the furnace. During the early stages of the heat treatment, particularly during start-ups, oxygen is purged out of the furnace with the achievement of positive internal pressure, preventing oxygen from re-entering the furnace during the Post Weld Heat Treatment cycle. This helps minimize oxidation to the component being heat treated.
Premium PWHT Services
do not have a furnace facility of our own but we offer a service to provide manpower, equipment and the gas distribution system to furnace facilities owned by our clients. The facility can be either a permanent or temporary furnace facility. Our equipment is flexible enough to be fitted to furnaces of any design – top hats, split roll off the modular structured furnace, fixed furnace with a movable hearth, etc. Our gas combustion equipment has the capacity to heat components up to 1000°C in a furnace facility intended to achieve normalizing or annealing purposes
We offer a specialized form of a heat treatment technique for the PWHT of very large structures such as spherical tanks, LPG bullet tanks and even thin-walled storage tanks. These structures are impossible to transport to a permanent heat treatment facility due to their massive sizes and weights. They are too large and heavy to be accommodated by any existing furnace facility anyway. We have the technology and experience to offer an in-situ heat treatment service that is of a more practical engineering solution. The technology involves the complete installation of thermal insulation to the structure’s exterior shell surface. The technique applied for the installation is capable of accommodating structural expansion and contraction during heat treatment. Strategic locations are identified for the purpose of burner insertion and exhaust flues.
High-velocity gas-fired burners are inserted into the vessel and fired directly into its internal atmosphere. This effectively converts the vessel into its own temporary self-contained furnace. The design of these burners is unique to the requirements of minimum pen flame lengths, thereby eliminating the potential dangers of direct flame impingement on the metal structure. Through careful planning of the burners and flue positions and proper manual controls on the burner velocity and flue dampers, a constant positive internal pressure is achieved to affect an intensive ‘scrubbing action’ of the hot gases against the structure’s wall surface. This is vital to achieving optimum temperature distribution and uniformity throughout the heating cycle in order to successfully complete the heat treatment process within governing engineering codes and heat treatment specifications. A procedure shall be prepared specifically for the job’s unique characteristics. This procedure is submitted for scrutiny and subsequent approval prior to the start-up of each project.
Refractory linings that are not properly and sufficiently dried out or cured, if subjected to sudden high-temperature exposures is likely to cause entrapped moisture content to convert into high-pressure steam. This will have detrimental effects on the component lined with refractory and in extreme conditions, can cause the refractory wall to implode – blowing out the refractory wall, severely damaging the component shell, reducing its life span considerably. This service is vital to any industry that utilizes Reactor vessels, Incinerators, Induction furnaces, Blast furnaces, Aluminum Holding furnaces, Knockout Pots, Cement Preheaters and Coolers, Refinery Crackers, Ladles and any other pressure vessels with refractory linings, high alumina bricks and castables. Our specially designed high-velocity burners are ideal for this nature of work that demands minute increments of temperature as stipulated in the dryout cycle. This is because of the gas combustion’s refined control system that is sensitive to high volume low-temperature conditions typical of a dryout requirement. The high-velocity burners are inserted at strategic locations together with damper flues and through manual controls, a positive pressure is achieved and maintained equally throughout the structure to effect proper temperature distribution and uniformity..
Another unique feature of these burners is their ability to allow for low gradual temperature increments of up to 5°C/hour or less. Temperatures are held at different intervals during their progress up to operating temperatures between 900°C to 1100°C to allow for proper heat penetration through the refractory walls. This is made possible to achieve with the burner’s low turndown ratio of 50 : 1 capability, which the furnace’s existing system burners are not designed to handle. All vents, inlets and outlets are temporarily blanked off with insulation bricks and thermally insulated bulkheads with the exception of flue apertures to minimize heat losses during the dryout/curing process.
Fabricators with an in-house heat treatment furnace will normally carry out their heat treatment requirements through it. However, there are often occasions whereby the length of the component exceeds the loading length of their furnace. Whilst extending the furnace length is an option, it’s frequently proven to be not only expensive but time-consuming as well. The other option would be to heat treat the component in two halves in their furnace and for the final seam, engage us for our expertise and capabilities to localize PWHT the final seam. This technique has been designed to take into consideration governing code requirements for the minimum heated band and insulated bandwidths respectively as well as the gradient temperature restrictions to prevent residual stresses from building up during the heat treatment process.
The technique requires temporary installation of thermally insulated bulkheads on either side of the closing seam to maintain heat retention within the heated area. Within this containment, specially designed heavy duty 240V rated four-bank channel elements are placed or alternatively, its equally rated ceramic pad mains heating elements are placed directly over the weld seam externally. The internal method involves systematic stacking of the 4-bank heaters within the component and the weld seam is heat-treated via radiated heat transfer. The external technique utilizes the principle of heat convection by placing the mains heaters directly onto the weldment around the full circumference on its external surface. Both alternatives require the placement of the bulkheads internally on either side of the weld seam for heat containment. These methods are approved to meet standard governing engineering codes and heat treatment specifications.
We are in the position to offer heat treatment services to existing offshore oil platforms during their shutdowns and repair works. We recognize the fact that such downtimes are extremely costly to the platform owners and have identified solutions to effectively reduce mobilization time to a significant level. Besides using the 50kVA transformers, which can be bulky to transport to the platform, the power requirement of each unit can also be a demanding factor on the platform’s existing power supply capabilities. For minor PWHT works, we also have the portable 2-zone temperature controllers that are designed for preheating and PWHT applications where AC/DC power source is available. It can draw its power from either the mains power supply or any available welding machine. The temperature controllers allow for semi-automatic controls, specifically during the Holding Temperature sequence. Our technicians are trained for offshore works and comply with all relevant documentation and safety passports required to work on the offshore platforms.