Needle valve works and installation precautions

Posted by uuuseff on November 19th, 2019

Needle valve works: The role of any valve is to cut off the fluid. According to the different spool, can be divided into globe valve, gate valve, plug valve, ball valve, butterfly valve, needle valve and so on. Needle valve valve than other types of valves to withstand greater pressure, good sealing performance, it is generally used for smaller flow, high pressure gas or liquid medium seal. Needle valve type and pressure gauge with the most appropriate use of the general needle valve made of thread connections. Nominal pressure: PN2.5 PN4 PN6.4 PN16 PN32Mpa Nominal diameter: DN5 ~ DN25 Suitable medium: oil, water, gas and other non-corrosive or corrosive media Suitable temperature: -20 ℃ ~ +440 ℃ -70 ℃ ~ -240 ℃ ≤540 ℃ ≤570 ℃ Manufacturing materials: 20 #, 1Cr18Ni9Ti, 304, 316, 316L, 12Cr1Mov and so on. Needle Valve Installation Notes: 1) Installation location, height, direction of import and export must meet the design requirements, pay attention to the flow direction of the medium should be consistent with the direction of the arrow marked body, the connection should be firmly. 2) The valve must be installed before the appearance inspection, the valve nameplate should be consistent with the current national standard "General Valve Marking" GB 12220 requirements. For the working pressure is greater than 1.0 MPa and the main pipe to play the role of cut-off valve, the installation should be carried out before the intensity and tightness test, qualified after the standard use. Strength test, the test pressure of 1.5 times the nominal pressure, the duration of not less than 5min, valve housing, packing should be no leakage as qualified. Tightness test, the test pressure of 1.1 times the nominal pressure; test duration in line with the requirements of GB 50243. Anticorrosion valve needle method: First, the anti-corrosion of the valve body, the main choice is the correct material. Although the anti-corrosion information is very rich, but it is not easy to choose the right thing, because the problem of corrosion is very complicated. The difficulty of choosing the valve body material lies in that it can not only consider the corrosion problem, but also must consider the ability of pressure and temperature resistance, economically reasonable and easy to purchase and other factors. Followed by the lining measures, such as lead-lined, lined with aluminum, lining engineering plastics, lined with natural rubber and various synthetic rubber. This is a saving method if the media conditions permit. Third, in the pressure, the temperature is not high, the valve body with non-metallic materials, often very effective control of corrosion.

Refrigerant gas R406A is a mixture of three components chlorodifluoromethane (R-22), isobutane (R-600a) and chlorodifluoroethane (R-142b) in the ratio 55/4/41. This refrigerant was designed as a drop-in replacement for R-12 which is compatible with the typical mineral oil lubricants used in R-12 systems. Since it is a zeotropic mixture, it has a range of boiling points which may increase the effectiveness of the heat transfer elements in refrigeration equipment.

R406A Refrigerant Gas

R406A Refrigerant Gas,R12 Replacement Gas,R406A Replacement Gas

ZHEJIANG ZHONGLAN REFRIGERATION TECHNOLOGY CO.,LTD , https://www.uiszl.com