The piping and plumbing fittings and valves articles discuss them further. Apex Supply is a wholesale distributor of plumbing, HVAC, industrial pipe and fittings. Pipe wrenches are not intended for regular use on hex nuts or other fittings. He also helped refine and develop improvements to existing plumbing and sanitary fittings. However, deionized water has been known to cause cracks in brass and copper fittings. Most of the various fittings made for metal conduit are also available in PVC form. Note that AN threads are different for bolts and fittings. There are many types of swaged fittings. Compression fittings are not as robust as soldered fittings. ProPress is a series of products based on copper pressed fittings. Redesigned interior fittings and passenger seats provide more seated headroom. Each of the legs was secured by two quick-release screw fittings on the firewall. They were given distinctive interior fittings. "Corrosion Proof Fittings v. the Environmental Protection Agency". Internal changes further included a restyled cabin with new materials and updated fittings.