Victaulic Company of America
Since 1925, the world leader in grooved and plain-end mechanical pipe joining systems. Victaulic offers complete, start-to-finish solutions that anticipate a project’s every need. The Victaulic grooved-piping method accommodates most piping materials, including lightwall, standard and extra-heavy duty steel, stainless, aluminum, ABS and other plastics, as well as underground-and waste-treatment process piping. ISO 9001 certified.
Watts 
Since 1874 a leading manufacturer of water safety & flow control products, backflow prevention devices, water quality & conditioning products, specification drainage products, brass & tubular products, control valves, potable PEX plumbing products, Quick-Connect Push Fit Solutions, and Custom OEM Products.
Wheatland Tube Company 
One of the world's leading manufacturers of continuous weld (CW) and electric resistance welded (ERW) pipe. Subsidiary of 128-year-old John Maneely Company, seven facilities manufacture pipe, tubing, fittings per ASTM, ANSI, UL, NEC, Federal Specifications. Wheatland's ASTM A-53 plumbing pipe and A-589 well water pipe are recognized for consistent quality.
QestPEX/Qest Hydronics
Zurn Plumbing Products Group - specializes in cross-linked polyethylene (PEX) tubing for use in potable plumbing, radiant heat, snow & ice melt, soil conditioning for greenhouses/stadiums and hot water baseboard distribution piping.
4specs Discussion Forum - Great place to ask questions about specifications, products and technical data. Free - no registration required to read or post (subject to moderation).
See also:
22 1055 - Plastic Piping, Valves and Fittings
33 1100 - Utility Services (Piping) (for piping primarily used outside the building 5' limits)
33 6140 - Pre-insulated Pipe Systems
QestPEX/Qest Hydronics
Zurn Plumbing Products Group - specializes in cross-linked polyethylene (PEX) tubing for use in potable plumbing, radiant heat, snow & ice melt, soil conditioning for greenhouses/stadiums and hot water baseboard distribution piping.
Victaulic Company of America
Since 1925, the world leader in grooved and plain-end mechanical pipe joining systems. Victaulic offers complete, start-to-finish solutions that anticipate a project’s every need. The Victaulic grooved-piping method accommodates most piping materials, including lightwall, standard and extra-heavy duty steel, stainless, aluminum, ABS and other plastics, as well as underground-and waste-treatment process piping. ISO 9001 certified.
Watts
Since 1874 a leading manufacturer of water safety & flow control products, backflow prevention devices, water quality & conditioning products, specification drainage products, brass & tubular products, control valves, potable PEX plumbing products, Quick-Connect Push Fit Solutions, and Custom OEM Products.
Wheatland Tube Company
One of the world's leading manufacturers of continuous weld (CW) and electric resistance welded (ERW) pipe. Subsidiary of 128-year-old John Maneely Company, seven facilities manufacture pipe, tubing, fittings per ASTM, ANSI, UL, NEC, Federal Specifications. Wheatland's ASTM A-53 plumbing pipe and A-589 well water pipe are recognized for consistent quality.