View all text of Subjgrp 74 [§ 230.70 - § 230.79]

§ 230.71 - Orifice testing of compressors.

(a) Frequency of testing. The compressor or compressors shall be tested for capacity by orifice test as often as conditions may require, but not less frequently than once every 92 service days.

(b) Orifice testing criteria. (1) Compressors in common use, as listed in the following table, shall have orifice test criteria as follows:

Make Compressor size Single strokes per minute Diameter of orifice
(in inches)
Air pressure maintained
(in pounds)
Westinghouse9 1/212011/6460 Westinghouse111003/1660 Westinghouse150 CFM 8 1/2 CC1009/3260 Westinghouse120 CFM 8 1/210015/6460 New York2a1205/3260 New York6a10013/6460 New York5b10015/6460

Note: This table shall be used for altitudes to and including 1,000 feet. For altitudes over 1,000 feet the speed of compressor may be increased 5 single strokes per minute for each 1,000 feet increase in altitude.

(2) For compressors not listed in the table in paragraph (b)(1) of this section, the air pressure to be maintained shall be no less than 80 percent of the manufacturer's rated capacity for the compressor.