Apollo

  Anvil
  Aquamine
  ASCO
  A. Y. McDonald
  A. W. Cash Valve Mfg. Corporation

  Babbitt Chain Wheels
  Bailey Controls

  Baum
  Beck/Blue Ridge Pipe & Nipple 

  Billco             
  Bristol Metals
  Camco Fittings Company
  Capitol Manufacturing Company

  Caro Polymers
  Catawissa
  Central Plastics
  Century Valve
  Cerro Tube
  Charlotte Pipe

  Check-All Valves
  Chemtrol

  Clow
  Conbraco
  Contech
  Dayco Imperial
  DeZurik
  Dixon Valve & Fitting
  Dresser Manufacturing Division
  Durabla Manufacturing Company
  Elomatic

  Ex-l-Tube

  Flying "w" Plastics

  FNW
  Gibson Tube
  Grinnell

  Ham-Let
  Hancor

  Hayward Mfg.
  Homestead Industries, Valve Division

  Howell Metal
  Imperial Eastman

  Indalex Alum.
  IPEX
  Ipsco Tubular

  ITT Engineered Valves
  Jamesbury
  JCM Clamps
  Kerkau
  Kerotest

Kunkle Valve Company
Ladish Company

Liberty Coatings
Lunkenheimer
Matryx
McElroy Mfg.
Merit Brass

Micromold
Modine

Morris Coupling
Mueller Brass Company
Mueller Steam
Nibco, Inc.

O.C. Keckley

OVC 

Penn Machine
Perfection Corporation
Phillips Drill Company
Phoenix Forge
PMV Positioners

Poly Pipe, Inc.
Powell Valve
PVI
RAMCO

Rath/Gilbson
Rectorseal Corp.

Red Valve
Resun
Ridgid Tool Company

Ritmo/America
RPS/ABCO
RUB
Sarco Company, Inc.
Schrader Bellows Division
Sharon Tube
Spirax/Sarco
Spraying System
Stockham Valve & Fitting
Taylor Forge
Tylok
Tube Forgings of America
Tufline XOMOX Corporation
US Steel Corporation
Victaulic Company of America

Ward Mfg.
Watson McDaniels
Watts Regulator Company
Wheatland Tube
Weldbend
Westlock Controls
Williams Valve
Zavoda