Advanced Special Valves For Gas Sampling Bags

                                                                     Dalian Hede Technologies Co.,Ltd.

      Gas sampling bags are important auxiliary consumables for gas analysis. The performance of gas sampling bag can largely affect the accuracy,the reliablity and repeatability of the gas analysis data.The valve is a key accessory to gas sampling bag performance.Valve in long contact with the gas sample inside bag,so the valve material must be chemical resistance,corrosion resistance,no precipitation of organic matter,no reaction with the gas sample,otherwise the valve can pollute the gas sample inside bag.

       Material selection and seal structure determine the performance of the valve.The design of the valve exterior also affects the valve whether to use convenient.The seal structure of special valvs for gas sampling bags are divided into soft seal structure and self-seal structure.

       Soft seal structure is adopted the method of soft elastic rubber seal combining with plastic or metal materials to cover and plug to seal the gas sample.Because of adopting rubber seal,soft seal structure can affect chemical resistance and corrosion resistance of the valve,and also can precipitate organic matter pollute the gas sample in bag.

       Self-seal structure is adopted the method of two smooth surface forming tight joint to seal the gas sample. There are materias can form smooth faces such as:

1.Plastic, such as: PE、PP、PC、ABS etc. 2.Metal, such as: copper、stainless steel etc. 3.Ceramics.

      These materials are strong resistance to chemical and corrosion,and no precipition organic matter so no pollution.self-seal structure is more adcanced and more reliable than soft seal structure.

      The film of gas sampling bag is thin soft and low strength,the inflation pressure of gas sampling bag is low(generally the working pressure is 3—6KPa,it's enough to fill the bag with gas, making the bag full up.)so it demands the special valves for gas sampling bags must be tight seal and small volume light quality and switch is easy to operate sampling.As a kind of lab analysis consumable,gas sampling bag must be low price to reduce the customer useage cost.So the special valves must have simple and reasonable design structure and advanced perfomance.

       Since1999 our company produced gas sampling bags we invested a lot of money to constantly study of special valves for gas sampling bags,successfully developed 10 kinds of special valves for gas sampling bags:ABS twist-type straight valve,copper vavle,(L-type) On/Off combination valve with side connector,stopcock straight valve,PC side-opening stopcock valve,slide pipe valve,needle type valve,piston valve,PTFE straight valve,side-opening PTFE valve.We have won four national utility model patents from 2005 to 2010,some of them have been applied for the US and Canada patent.

       In 2009 our company designed and developed the gas sampling bags with stopcock valves got National UtilityModel Patent,and applied for USA and Canada patents,which compared withthe valves in home and abroad have significant advancements.