Pressure Leak Test Research Articles

Occupational Exposure of Veterinarians to Waste Anesthetic Gases

Abstract An evaluation of anesthetic waste gas exposures was conducted in small private practice animal clinics throughout the Salt Lake Valley. The two most frequently used anesthetic gases, methoxyflurane and halothane, were chosen to be studied. Exposures during 38 surgeries were studied in a total of 10 facilities involving 13 veterinarians. Veterinarian breathing zones were sampled on a real-time basis with a Wilks Miran infrared analyzer. Several back-to-back surgeries were also monitored to determine the potential for gas build-up in the operating rooms. The monitoring results indicated that veterinarians have a significant exposure to anesthetic gases. Time-weighted averages over the anesthetic administration period ranged from 0.07 to 2.99 ppm for methoxyflurane and from 0.08 to 9.19 ppm for halothane. A low pressure leak test was performed on each piece of anesthesia equipment. Of the 20 machines checked, 55 percent did not meet the NIOSH recommendations concerning maximum leakage of 100 ml/min ...

Development of tin plated high seal buttress casing joint.

API Buttress Thread Connection (B.T.C.) has high joint strength, but lacks internal pressure sealability. A spiral leak path of threading tolerance on the mating surface causes the leakage.With an object of improving seal capability of the joint, thick tin plating was applied on the threads of coupling to fill the potential leak path.However thick plating increases thread interference, which might influence the joint performances. Therefore optimum plating thickness should be determined taking these into account.Makeup tests, hydrostatic internal pressure leak tests and joint tensile tests were conducted to study the joint properties. Samples of three different plating thickness levels-20μ, 60μ and 120μ-were tested.As the results of the tests, (1) Thick tin plating improves the sealability of a Buttress Thread Connection.(2) Makeup stress and the first part of makeup torque increase in proportion to the plating thickness.(3) Joint strength was not influenced by the tin plating on the thread. And at last, 60μ level tin plating thickness is considered to be the most pertinent for a Buttress Thread Connection to improve the sealability without decreasing the other joint properties.