《泄压阀的最低要求外文翻译》由会员分享，可在线阅读，更多相关《泄压阀的最低要求外文翻译（14页珍藏版）》请在金锄头文库上搜索。
1、MINIMUM REQUIREMENTS FORPRESSURE RELIEF VALVESUG-136(a) Mechanical RequirementsUG-136(a) (1) the design shall incorporate guiding arrangements necessary to ensure consistent operation and tightness.UG-136(a) (2) The spring shall be designed so that the full lift spring compression shall be no greate
2、r than 80% of the nominal solid defection. The permanent set of the spring (dened as the difference between the freeheight and height measured 10 min after the spring has been compressed solid three additional times after presetting at room temperature) shall not exceed 0.5% of the free height.UG-13
3、6(a)(3) Each pressure relief valve on air, water over 140F (60C), or steam service shall have a substantial lifting device， which when activated will release the seating force on the disk when the pressureRelief valve is subjected to a pressure of at least 75% of the set pressure of the valve. Pilot
4、 operated pressure relief valves used on these services shall be provided with either a lifting device as described above or means for connecting and applying pressure to the pilot adequate to verify that the moving parts critical to proper operation are free to move.UG-136(a) (4) the seat of a pres
5、sure relief valve shall be fastened to the body of the pressure relief valve in such a way that there is no possibility of the seat lifting.UG-136(a) (5) in the design of the body of the pressure relief valve, consideration shall be given to minimizing the effects of deposits.UG-136(a) (6) Pressure
6、relief valves having screwed inlet or outlet connections shall be provided with wrenching surfaces to allow for normal installation without damaging operating parts.UG-136(a) (7) Means shall be provided in the design of all pressure relief valves for use under this Division for sealing all initial a
7、djustments which can be made without disassembly of the valve. Seals shall be installed by the Manufacturer or Assembler at the time of initial adjustment. Seals shall be installed in a manner to prevent changing the adjustment without breaking the seal. For pressure relief valves larger1 Than NPS 1
8、|2 (DN 15), the seal shall serve as a means of identifying the Manufacturer Or Assembler making the initial adjustment.UG-136(a) (8) If the design of a pressure relief valve is such that liquid can collect on the discharge side of the disk, except as permitted in (a)(9) below, the valve shall be equ
9、ipped with a drain at the lowest point where liquid can collect (for installation, see UG-135).UG-136(a) (9) Pressure relief valves that cannot be equipped with a drain as required in (a) (8) above because of design or application may be used provided:(a) The pressure relief valves are used only on
10、gas service where there is neither liquid discharged from the valve nor liquid formed by condensation on the discharge side of the valve; and(b) the pressure relief valves are provided with a cover or discharge piping per UG-135(f) to prevent liquid or other contaminant from entering the discharge s
11、ide of the valve; and(c) The pressure relief valve is marked FOR GAS SERVICE ONLY in addition to the requirements of UG-129.UG-136(a) (10) for pressure relief valves of the diaphragm type, the space above the diaphragm shall be vented to prevent a buildup of pressure above the diaphragm. Pressure re
12、lief valves of the diaphragm type shall be designed so that failure or deterioration of the diaphragm material will not impair the ability of the valve to relieve at the rated capacity.UG-136(b) Material SelectionsUG-136(b) (1) Cast iron seats and disks are not permitted.UG-136(b) (2) Adjacent slidi
13、ng surfaces such as guides and disks or disk holders shall both be of corrosion resistant material. Springs of corrosion resistant material or having a corrosion resistant coating are required. The seats and disks of pressure relief valves shall be of suitable material to resist corrosion by the uid
14、 to be contained.NOTE: The degree of corrosion resistance, appropriate to the intendedservice, shall be a matter of agreement between the manufacturer andThe purchaser.UG-136(b)(3) Materials used in bodies and bonnets or yokes shall be listed in Section II and this Division.Carbon and low alloy stee
15、l bodies, bonnets, yokes and bolting (UG-20) subject to in-service temperatures colder than 20F(30C) shall meet the requirements of UCS-66, unless exempted by the following.(a) The coincident ratio dened in Fig. UCS-66.1 is 0.35 or less.(b) The material(s) is exempted from impact testing per Fig. UC
16、S-66.UG-136(b) (4) Materials used in nozzles, disks, and other parts contained within the external structure of the pressure relief valves shall be one of the following categories:(a) Listed in Section II;(b) listed in ASTM specications;(c) Controlled by the Manufacturer of the pressure relief valve by a specication ensuring control of chemical and physical properties and quality at least equivalent to ASTM stan
