API 526 7th 2017 pdf free download
API 526 7th 2017 pdf free download.Flanged Steel Pressure-relief Valves.
4 Responsibility 4.1 The purchaser is primarily responsible for the following: a) selecting the type of pressure-relief valve and the required pressure-temperature ratings; b) specifying materials that will satisfactorily resist corrosion from the process fluid and environmental conditions; c) selecting the minimum required orifice area based upon relieving conditions derived from full knowledge of the pressure-relieving system and the requirements of the applicable codes and regulations; d) providing data for sizing and selection. 4.2 The manufacturer is primarily responsible for the following: a) designing and manufacturing pressure-relief valves to satisfy the requirements of this standard and the purchaser’s specification; b) publishing relieving capacities based upon certified test data; c) advising the purchaser of any nonconformance to the purchaser’s specification; d) final sizing verification using the manufacturer’s actual orifice area and certified coefficient of discharge. 5 Conflicting Requirements Whenever the information included on the purchaser’s specification sheet or purchase order conflicts with the provisions of this standard, the purchaser’s specification sheet or purchase order shall govern. Where conflicting requirements exist, the manufacturer shall call them to the attention of the purchaser. 6 Orifice Areas and Designations The standard effective orifice areas and the corresponding letter designations are listed in Table 1. These effective areas are valid only when used with the sizing equations contained in API 520, Part I.
b) The rated capacity for restricted lift valves shall be in accordance with ASME BPVC, Section VIII. Note that ASME prohibits restricting the lift to a value less than 30 % of the full rated lift, or less than 0.080 in. The restricted lift relief device shall meet all requirements of this document (e.g. face-to-face dimensions) for the standard valve with the exception of the restriction in lift. c) The final relief device design shall meet the requirements in ASME BPVC, Section VIII. The restriction of the relief device lift shall only be performed by the valve Manufacturer or Assembler per ASME BPVC, Section VIII. d) The nameplate on restricted lift relief devices shall be stamped to identify the reduced lift value and the rated capacity based on that reduced lift value. e) Restricted lift versions of the pressure-relief valves in Table 3 through Table 30 may be specified by providing the manufacturer with a required capacity and the maximum desired rated capacity. The manufacturer shall determine the lift that will provide a rated capacity within these two values. Prior to making a final selection the purchaser shall confirm that the restricted lift relief device meets the design requirements (see example in Annex E). 8 Material 8.1 General Materials generally used for construction are covered in this section. For special corrosion problems and applications beyond the pressure–temperature limits of this standard, construction materials shall be those agreed upon by the manufacturer and the purchaser. 8.2 Spring-loaded Pressure-relief Valves The body and bonnet materials shall be in accordance with Table 3 through Table 16 for the required temperature range. The body and bonnet may be of different materials but must meet the minimum pressure–temperature requirement. The body and bonnet materials shall be equivalent to or better than the following types and grades: — carbon steel, ASME SA-216, Grade WCB;
10.2 Preparation for Shipment Each pressure-relief valve shall be prepared for shipment as follows. a) After test and inspection, all exterior surfaces, except flange facings, shall be painted as agreed upon by the manufacturer and the purchaser. Corrosion-resistant materials need not be painted. Flange facings shall be coated with a suitable corrosion inhibitor. b) Threaded openings shall be plugged with suitable protective devices. Temporary plugs should be readily distinguishable from permanent metal plugs. c) Inlet and outlet flanges shall be protected to prevent damage from or entrance of foreign material during shipment. 11 Pressure–temperature Tables Table 3 through Table 30 provide flange and bellows pressure limits, materials and dimensions for pressure-relief valves. Table 3 through Table 16 are specific to spring-loaded pressure-relief valves, while Table 17 through Table 30 are specific to pilot-operated pressure-relief valves. 11.1 Materials Materials for the body/bonnet and springs are indicated for spring-loaded pressure-relief valves. The material for the body is indicated for pilot-operated pressure-relief valves. For further description of body and bonnet materials see 8.2 for spring-loaded pressure-relief valves and 8.3 for pilot-operated pressure-relief valves. Other combinations of pressure, temperature, size and materials are outside the scope of this standard. 11.2 Temperature Ranges Temperature ranges are provided to indicate distinct changes in body and/or spring material requirements. 11.3 Maximum Inlet Flange Pressure The maximum inlet flange pressure is provided at specific temperatures.
