歡迎訪問中科光析科學(xué)技術(shù)研究所官網(wǎng)!
免費(fèi)咨詢熱線
400-635-0567
通用金屬蝶閥檢測項(xiàng)目報(bào)價(jià)???解決方案???檢測周期???樣品要求? |
點(diǎn) 擊 解 答??![]() |
This International Standard specifies the requirements for metallic butterfly valves — with centred or eccentric disc, — with centred or eccentric shaft, — with metallic, polymeric, elastomeric or composite seating, — with lined or unlined body, — coated or uncoated, to be used in flanged or butt-welded piping systems for shut-off, throttling or flow control. It covers butterfly valves with nominal diameters DN 40; 50; 65; 80; 100; 125; 150; 200; 250; 300; 350; 400; 450; 500; 550; 600; 650; 700; 750; 800; 900; 1 000; 1 200; 1 400; 1 600; 1 800; 2 000; and is applicable to valves of nominal pressure PN 2,5; 6; 10; 16; 20; 25; 40; 50.
This European Standard specifies minimum general requirements for butterfly valves having metallic bodies for use in wafer, lug, flange or butt welding piping systems and used for isolating, regulating or control applications. The PN and Class ranges are: - PN 2,5; PN 6; PN 10; PN 16; PN 25; PN 40; PN 63; PN 100; PN 160; - Class 150; Class 300; Class 600; Class 900. The DN range is: - DN 20; DN 25; DN 32; DN 40; DN 50; DN 65; DN 80; DN 100; DN 125; DN 150; DN 200; DN 250; DN 300; DN 350; DN 400; DN 450; DN 500; DN 600; DN 700; DN 750; DN 800; DN 900; DN 1000; DN 1100; DN 1200; DN 1400; DN 1500; DN 1600; DN 1800; DN 2000; DN 2200; DN 2400; DN 2600; DN 2800; DN 3000; DN 3200; DN 3400; DN 3600; DN 3800; DN 4000.
This part of ISO 28921 specifies requirements for the type testing of isolating valves for low-temperature applications to verify the performance of valves at a low temperature from -50 °C down to -196 °C. NOTE Nominal sizes (DN), nominal pipe sizes (NPS), nominal pressure (PN) and Classes are covered in ISO 28921-1. This part of ISO 28921 does not evaluate valve actuators unless they are integral part of the valve. Valves during testing can be operated manually or an actuator can be used during the testing. The effect of cold gas vapours during testing is taken into consideration in particular if the actuator is mounted directly over the test stand with the cold gases engulfing the actuator. This part of ISO 28921 does not apply to valves for cryogenic services, designed in accordance with ISO 21011, used with cryogenic vessels.