Failed Steam Trap Damage

 Fixed Orifices VS Conventional Steam Traps

 Nuclear Regulatory Commission Report




Model A100 Plug Resistant Orifice for Turbine Drains

View and Print A-100 Brochure

The Model A100, plug resistant orifice, has been used in power plants around the world since 1971, and has proven its reliability in the most demanding of services. It is rated for 3675 psig @1000F, OR 2625 psig @ 1050F. It was designed to prevent inadvertent water induction into turbine cylinders by replacing failure- prone steam traps. We manufactures Model A100 Plug Resistant Orifice for Turbine Steam Line Drains.

The A100 is often used in the gland seal drain systems and in other steam supply drain lines where steam traps were once used. The A100 consists of two parts: the plug and the body. The strainer holes are sized to trap particles that might otherwise plug the basic orifice. This filter system does away with fragile wire cloth strainers that can fail or plug up. The plug can be removed from the body for inspection and cleaning without breaking any lines.

The Model A300 is similar to the A100 but features an additional side port to accommodate a bypass or on-line cleanout. Both parts of the assembly are fabricated from forged bar stock ASME-SA-479-316SS. Steam traps should be replaced with plug resistant orifices in critical systems and high pressure systems because:

  • Compared to a 1/16" fixed orifice, when a steam trap fails open the amount of energy lost can be colossal. A 1/4" trap that has failed open in a 600psig system will waste approximately $40,000 per year.
  • When a steam trap fails closed the damage can be devastating. ASME Std TDP-1-1998 (Water Damage to Steam Turbines) par 3.11.9 states "Steam traps are not satisfactory as the only means of drainage of critical drain lines."
  • A British government report is available describing the many advantages of fixed orifices over conventional steam traps including reduced maintenance and elimination of water hammer.


Plug Resistant Orifices | Orifice Steam Traps | Steam Vent Silencer | Turbine Drains | Blowoff Silencer
Boiler Feed Pump Recirculation | Pump Spillback | Gas Vent Silencer | Eliminate Valve Cavitation
Flow Restriction Orifices | Steam Line Drains | Breakdown Orifices | Pipeline Blowdown Silencer
Multi-Stage Orifices | Blowdown Silencer

CU Services LLC | 725 Parkview Cir. | Elk Grove Vlg, IL  60007
Phone: 847.439.2303

Copyright © 1971 - 2004 CU Services LLC & Thermal Analysis Systems Co. All rights reserved.