[MrHPI]

For 30 years we have been using an outside weld shop to weld the hydraulic cylinders we manufacture. They weld bases into the cylinder tubes, ports onto the OD of the tubes, and various types of mounting to the tube and/or endcaps. The bases and ports see up to 3,000 PSI from the hydraulic fluid and the mountings see the force created by the cylinder during actuation. The bore sizes range from 1-1/2" to 12". If we decide to bring some of the welding in house to do ourselves, what kind of welding would be best, fastest, least expensive to do while maintaining the strength required for this type of applicaiton? Thanks for any and all advice.

[weldin mike 27]

Hey there,
Possibly some kind of Metal Cored mig welding. The metal cored wire contains special alloys to provide very good penetration as well as weld metal quality.

Mick

[Otto Nobedder]

In the U.S., the pressure welds (seeing direct hydraulic pressure) will probably fall under ASME. I don't know what section, offhand, but a little research along those lines might lead you in the right direction. Having ASME code certification, where it applies, is a MUST to be able to insure yourself against liability for your work. The code will guide you as to the correct welding methods, NDT, welder certification tests, etc.

As for the structural attachments, I don't know if ASME has a section for that, but if they do I'd take that path. If not, AWS section D1.1 should provide guidance in the acceptible methods, load calculations, inspection, etc.

Clear as mud? I'd consider hiring a consultant on this issue, preferably a liscenced PE, because to bring this in-house, you don't want to get it wrong.

Steve S.