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PWT has on its staff one of the foremost resistance welding system experts in the industry.

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As with our fusion and electron beam welding system services, we now supply preventive maintenance, corrective maintenance, calibration, and training on all resistance welding equipment.

Our preventative maintenance program involves analyzing the machine's electrical, mechanical, pneumatic, and water-cooling systems. We will check and compare with the previous maintenance/operator's logs to determine and trend whether a particular system in the welder is deteriorating at an accelerated rate, and calibrate all critical machine weld parameters. We also utilize temperature and load/stress sensors on the welding machine to determine how the machine is performing under loaded conditions. The following, at a minimum, should be checked: Incoming Line Voltage, Primary Current, Secondary Current, Secondary Voltage, Testing of Automatic Voltage Correction (AVC) system, Welding Time, Pressure System, Secondary Resistance, and all electrical and mechanical connections.

Capabilities PWT brings to your operation:

• Availability of expertise: our resident expert is based in the Chicago area, so we are centrally located to support equipment from coast to coast, and overseas.
   
• Availability of parts: we have many common spare parts for your spot or seam welder at either our Carson City, Nevada warehouse, or our Chicago facility.
   
• Test experience: we have experience testing and installing resistance welders, design of wiring interconnection, and retrofitting spot & seam welders with many new systems, including CNC Controls, PLCs, and touch-screens.
   
• Weld process development experience: we have experience with weld process development resulting in optimum parameter selection for welding all types of metals including dissimilar alloys such as Aluminum to Steel, Niobium to Titanium, etc. In order to yield ideal nugget formation and resultant weld strength, we can help you with optimizing parameters such as electrode force (pressure), current, firing angle, and time (cycles). We also know how to select the maximum heat input or weld impulse heat cycles as well as heat current and current decay, by applying the machine's K factor to avoid damage to your machine's transformer. To counteract electrode wear and erosion, we can employ many process and material strategies with the objective to increase electrode or tip life and welding performance.
   
• Equipment optimization skills and experience: we can help you optimize equipment selection for your part applications. Considerations should be the machine's kVA, secondary current, duty cycle, welding and forging force, pulsation, and electrode configuration including proper throat depth and gap, as well as offset loading of ram.
   
• Breadth and depth of knowledge:
  • We have knowledge on single-phase AC resistance welding machines, conventional DC welding machines, three-phase low-frequency welders, and three-phase medium-frequency direct current (MFDC) inverter-type welding systems.
  • We understand how to meet the industry standard Class A, Class B, and Class C MIL-SPEC specifications in order to certify your welding equipment.
  • We can get your welds to conform to AWS D17.2/D17.2M:2007 and MIL-W-6858.

PWT can support resistance welding equipment from several manufacturers and we offer upgrades or retrofits on many machines. Some of the common upgrades we offer:
              CNC Control/PLC   |   Servo Drive   |   Upper & Lower Head Assembly Refurbishment   |   Programmable Transducer

 

CNC Control/PLC

Benefits of the retrofit are the following:

• Minimize Spot & Seam Welding System failures
• Allow customer to run in automated mode
• More reliable than most other resistance weld system controls in the industry, due to reduced component count, resulting in fewer failures
• Off-the-shelf replacement parts
• Simple to program
• Operating system is familiar to most computer users
• Control designed for low frequency operation

Some of our CNC control features are as follows:

• PC-based software
• Standard G-code programming for motion control
• Seemingly unlimited part program storage
• Ethernet connectivity, including 2-axis Ethernet motion control card
• 32-point optical isolated relay card
• Windows XP operating system
• Swing arm 17 inch monitor
• NEMA 12 enclosure

Individual weld system control features include:

• Microprocessor-based weld control
• Solid-state 3-phase AVC control
• Programmable weld/forge closed-loop integrated pressure controller accurate to +/- 1%
• 140 programmable weld schedules
• Isolation & firing boards to fire existing SCRs
• Custom cable assemblies w/ terminal strip

Servo Drive

See our EBW Components page for more information.

Upper & Lower Head Assembly Refurbishment (Seam Welder Only)

Benefits of the retrofit are the following:

• Proper and efficient head operation for many years to come resulting in better welds
• Less downstream maintenance of the critical head assembly required

The retrofit consists of installing the following new components:

• Silver Shoe, comprising many components, such as springs, that wear
• Certain machines may require a specially designed spacer, in order to set the correct spring pressure at the shoe
• Many other components in the head which wear or degrade such as bearings, seals (causing water leaks), etc.

(select to see larger version)Programmable Transducer

Using current-to-pressure programmable controls ensures accurate pressure control.

Two styles are offered:

• PROPORTION-AIR
• Air Programmable Inc.

Benefits of the retrofit are the following:

• Minimize transducer failures
• Minimize air system variability from line air pressure drops and surges
• Maximize consistent welding force via fast response piston regulator on input and volume booster on output
• Improve system reliability via constant, consistent air pressure to transducer input as noted in transducer specifications

The retrofit consists of installing the following new components:

• Five micron filter w/ sight glass
• Air reservoir, capacity calculated by "free air consumption" formula
• Ball valves
• Volume booster
• Five port / 4-way, 120VAC or 24VDC solenoid air valve
• Miscellaneous connectors, fittings, clamps, etc.

              Advanced Spot Welder   |   Advanced Seam Welder

 

Advanced Spot Welder for Sale
 

Sciaky 150KVA Spot Welding System w/ Touchweld Control (Refurbished)

The machine we are offering looks and runs like it is brand new. It is a Touchweld computer controlled, fully integrated, 150KVA Spot Welding system (Model SPTM2-30-150-36), capable of 3,000 lbs. force, and previously used by a major airline for spot welding turbine engine components. This machine will contain many new components and have the critical secondary circuit connections newly silver plated. The machine will also contain reliable and repeatable electronic components for accurate processing control of the customer's hardware and includes the following features: Touchweld Cabinet & Full Complement of PC Boards, such as, AVC & Zero Crossing Power Fail Detector Motherboard Pulse Firing Daughterboard SCR Firing LED Display Microprocessor & Other Critical Components   “Like New” Weld Heads   Pressure System   Programmable Weld Schedules   “Like New” Power Supplies   “Like New” Air & Water Switches   Transformers   Electronic Circuits   Schematics and OEM Instruction Manuals

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With purchase of this machine, we will provide a complete installation/startup which would include electrical hookup, startup, machine calibration, and informal operator training.

Advanced Seam Welder for Sale

Also for sale, but not yet refurbished, is the above machine's cousin: a Touchweld computer-controlled, fully integrated, 150KVA Seam Welding System (Model MPT.2-30-150-36).