Pipeline PWHT Stress Relieving After Welding


Steel plates-Pipeline PWHT stress relieving after welding,preheating for welding,induction post welding,welding preheat blankets,induction preheating metal before welding,post welding heat treatment.

MYD series of induction heating system are used for weld, bending, piping, coating, fitting, stress relief, pre-weld heat and post-weld heat treatment


Model and Technical Parameters

Input Power3*380VAC (Default), 3*220VAC (Optional), 3*440VAC (Optional)
Output Frequency2KHZ ~ 30KHZ
Output Power40KW50KW60KW80KW100KW120KW
Input Current60A75A90A120A150A180A
Air CoolingHeating size:¢100-1500mmSize: 800*560*1350mm
DSP controlMax:900℃; Heating Speed: 5-400℃/minPacking size:900*660*1560mm
6 Channels control10 curves recorderNet weight: 120kgGross weight with parts: 155-260kg
Main partsInduction coilK ThermocoupleR-1006 Temperature Recorder
Connection cableInsulation BlanketThermocouple Connection cable

PWHT manufacturer

● Input Voltage: 380V, 3 phase, 50/60HZ

● Output Frequency: 2KHZ ~ 30KHZ

● Output Power: 2KW ~ 40KW

● Cooling: air cooled

●  Heating Speed: 5-400℃ per minute

● Heating temperature range: -30℃-900℃

● Heating parts size range:¢100-1500mmor equal

● Induction coil: 10-45meters long high temperature cable with air cooled

● Temperature recorder: 6 Channels for temperature controlling

● Thermocouple: K Type (5-45 Meters long link cable)

● Size: 800*560*1350mm Net weight: 120kg; Packing size:900*660*1560mm, Gross weight: 155kg.

The option parts of induction heating system

● Induction heating power

● Induction coil (Clamp induction coil) or (Soft induction coil)

● Connection cable for the convenient to link the coil and the heating power

● Temperature controller

● PLC touch screen

● Temperature recorder with printer

● K type thermocouple&connection cable

● Insulation Blanket

● And other part.

MYD series induction PWHT weld heater to compare the resistant heat:

● Uniform

● High Speed

● Energy Saving: 30-80%


● Air cooling: working well at -10℃-40℃

● Induction heating power: To heat the work job with insulation blanket around it. High heating speed and heating efficiency with little energy lost.

● PLC touching screen: Intuitive to see and easy to operate.

● Soft induction coil: Easy to wind on different work piece.

● The Removable opening Induction coil: easy to operate and move.

● Temperature recorder: Record the whole heating curve.

● Temperature Controller: Heating according to the heating requirement details with the ±3℃ tolerance.

Applications&using fields

Our MYD series heating system are air-cooled induction heating equipment with DSP system.

Their main applications are pipeline heat, pre-weld heat, post-weld heat treatment, stress relief, injection mold heating, annealing, etc.

● Pre-heat:for coating, bending, fitting&unfitting, weld.

● Post-weld heat treatment: tank, boiler or other metal jobs

● Heating: mold heating, shipboard, zinc bath, large& irregular metal parts

● Pipeline heat: pipeline oil, pipeline gas, pipeline water, pipeline petrochemical and other pipeline material

The using fields involved are petrochemical, oil and gas pipelines, aerospace, shipbuilding, steel, tanks, boilers, vessels, pressure vessels, cylinders, metal structure, spatial structure, railway bridges, electricity water, mine construction, vehicle manufacturing, nuclear power, mining, plastics processing, energy saving process, mold, screw barrel

Ø Heaters and parts for choice

1.MYD-40KW heater
3.MYD-60KW heater
4.MYD-80KW heater
5.25m cable coil(air cooling)Quick heat
6.25m cable coil(water cooling)
7.25m cable coil(high temperature)
8.Insulation blanket           (800℃ 1500*600*50mm)
9.Insulation blanket           (800℃ 900*600*50mm)
10.K type thermcouple            with 2m cable
11.Thermonuclear Extend

Cable 10m

12.Connection Cable for

coil 10m


Temperature recorder


MYD induction heating machine for weld heat and heat treatment(PWHT)

1. Weld joint heating&heat treatment(PWHT):steel pipeline, steel structure and steel sheet

2. Heating and insulation: pipeline liquild, reactor,kettle, boiler, tank

3. Thermal assembly Heating: bearing, axle sleeve, engine motor and motor shell

4. Hot drying: food material, metal, printing film drying and heat-shrink film

5. Factory warming: oil, gas and water heating

6. Coating heating: pipeline, steel board

7. Melting: copper,aluminum,tin,zinc,lead

Differences between MYD Series and MYDS Series induction heater

ItemPower(KW)PLC Cooling typeCoil CoolingMax TemperaturePower SizeCoil Length
MYD≦36010Air cooling


Air for preheat

Water for PWHT

MYDS≦3604.3Air cooling


ItemUSB:DSPRecorder ConnectorHeating curve StorageThermocouple


Remote controlCoil Connector


Main applications of MYD Series and MYDS Series induction weld heater

ItemPreheatWeld heatPWHTThermal AssemblyReactor heatingTank heatingInjection

Mold heating

WaterGasOilPipeline Liquid

Difference between MYD induction weld heater and ceramic pad heating elements(Quick heating)

ItemHeatInsulationHeating elementsHeating lostSpeedEfficiencyUniformity
InductionDirectInnerLess hotLessHighHighMore

Product Enquiry