Many energy conservation programs start with a steam trap survey because leaking traps can raise a company’s overhead operating expenses by as much as a third. Energy audits and repairs often save companies hundreds of thousands of dollars.

Experts estimate that in a plant with no active steam trap testing and repair program, 50% of the traps are blowing steam. With monthly inspection and prompt repair, this figure can be reduced to under 3%. Example: One trap with a 3/32″ orifice operating at 100 psi can lost almost 30 lbs. of steam per hour. At $8/1,000 lbs. of steam, that can result in a loss of over $2,000 a year from each faulty trap of that type.

Ultrasonic testing can quickly reveal the condition of each steam trap. In fact, the major trap manufacturers recommend regular testing. An ultrasonic test is a “positive” in that a user can hear what is happening within a steam system as it is being tested. A contact probe used to localize the sound coming from the trap will not pick up the other pipe noises since ultrasound intensity falls off rapidly as it moves away from its source.

Generally speaking, there are two types of steam traps: intermittent and continuous flow. Intermittent traps normally operate in a cycle of open-close-open-close. Continuous-flow traps usually modulate according to condensate load and a failure most often occurs in the closed position. Continuous flow traps include float, float & thermostatic and thermostatic (bellows). A failure usually occurs in the open position causing a constant rushing sound. Each trap in this category has its own particular method of operation and pattern of open-close. Other intermittent traps include inverted bucket, bucket, thermodynamic (disk), bi-metallic and, at times, thermostatic. The cessation of typical operating sound signifies trap failure.

Testing services utilize the latest technology in ultrasonic equipment and the most comprehensive steam trap software available. Each trap’s number, location, application, size, manufacturer and model number are logged in. After thorough documentation, the trap is ultrasonically tested. Ultrasound heterodynes the operational sound of the steam trap and actually allows us to hear the trap’s operation. It is the only positive test available which accurately and instantaneously allows a performance evaluation of the trap to be made. After the ultrasonic test is completed, infrared temperature readings are taken at the inlet and outlet of the trap. This data is then documented for later calculation of inlet and outlet pressures.

In a system of 1,000 steam traps, it is assumed that the average orifice size of a blow-through is estimated at 1/16 inch, the average pressure is 150 psig, and the cost of steam production is $4.00/1,000 lbs. It is also assumed that the plant steam is in operation 365 days/year, 24 hours/day. Based on these assumptions, the steam loss per day is 453 lbs. per trap at a cost of $1.81/day/trap or $662.25/year loss per trap. A conservative assumption that only 10% of the traps are faulty would result in an annual cost of $66,225 in lost steam within the system.