1) the cause of valve leakage during construction:

â‘  improper transportation and lifting caused the valve damage as a whole resulting in valve leakage;

â‘¡ When leaving the factory, no pressure is applied to the valve for drying and antiseptic treatment, resulting in corrosion of the sealing surface to form internal leakage;

â‘¢ construction site protection is not in place, the valve is not installed at both ends of the blind, rain, sand and other impurities into the seat, resulting in leakage;

â‘£ installation, there is no grease on the seat, resulting in impurities into the seat back, or welding caused by burns within the leak;

⑤ valve is not installed in the full position, resulting in ball damage, welding, if the valve is not fully open, welding spatter will cause damage to the ball, when the ball with welding spatter in the switch will further damage the valve seat , Resulting in internal leakage;

â‘¥ welding residue and other construction caused by the sealing surface scratches;

⑦ factory or installation limit is not accurate cause leakage, if the valve stem drive sleeve or other accessories with the wrong angle of the assembly, the valve will leak.

2) Run-time valve leakage caused by the reasons:

â‘  The most common reason is that operators consider the more expensive maintenance costs of the valve does not maintain or lack of scientific management and maintenance of the valve is not preventive maintenance of the valve, resulting in premature failure of equipment;

â‘¡ improper operation or maintenance procedures in accordance with the maintenance caused by internal leakage;

â‘¢ In normal operation, the construction residue scratches the sealing surface, resulting in internal leakage;

â‘£ improper pigging caused by sealing surface damage caused by leakage;

⑤ long-term maintenance or inaction of the valve, resulting in valve seat and the ball lock, resulting in sealing the valve leakage caused by internal leakage;

⑥ valve switch is not in place to cause internal leakage, any ball valve regardless of open, closed position, the general tilt 2 ° ~ 3 ° may cause leakage [2];

⑦ many large-diameter ball valve stem stopper most have, if the use of a long time, due to corrosion and other reasons in the stem and stem stopper will accumulate rust, dust, paint and other debris, these debris will cause the valve Can not rotate in place and cause a leak - If the valve is buried, lengthening the stem will produce and drop more rust and impurities prevent the ball from rotating in place, causing the valve to leak,

⑧ general implementing agencies are also limited, if long-term cause corrosion, grease hardening or limit bolt loose limit will not be accurate, resulting in internal leakage;

⑨ electric actuator set the valve position in front, no place in place caused by internal leakage;

â‘© lack of periodic maintenance and repair, resulting in sealant dry, hardened, dried Sealing grease accumulation in the elastic seat, hinder the seat movement, resulting in seal failure.

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 Plastic Extruder / Extrusion Machine / extruding equipment 
Product application of pvc pipe conical twin screw extruding machine

SJSZ series conical twin screw stem extruder is composed of barrel screw, gear transmission system, measurable feeding, vacuum deareating, heating, cooling and electric control components ect. It is mainly used in plasticizing, extruding and forming of PVC pipes, plates, sheets, film , profiles, and granules, ect.

High recovery rate PET plastic Pellet Machine

1. Description
Twin screw extruder recycling & pelletizing system are applied to the waste materials,which needs high processing performance of melting,volatilization,filtering etc.,mainly works for the job of PET scraps recycling and re-pelletizing.
To slow down IV value reducing during PET scraps recycling,not only impurities,such as PVC content,moisture,etc.,but also precise recycling system and reliable equipment configurations are necessary to put in the solution. 
2. Pre-processing equipment required according to the condition of various PET scraps;
Special designed compactor applied to handle low bulk density scraps,such as film,filament,etc
Pre-crystallization system is required to pre-dry PET regrinds,flakes to guarantee final productions quality.
Main technical parameter:
Machinery Size Data of Compactor Data of twin screw extruder Throughout rate(Kg/hr)
Efficiency Volume(Liter) Motor power(Kw) Diameter of screw(mm) L/D Motor power(Kw)
ACT800/75 800 90 71.2 36 132 350-450
ACT1000/95 1000 110 91 36 200 500-600
ACT1200/95 1200 132 91 36 250 600-800

Plastic Extrusion And Recovery Equipment

Twin-Screw Extruder, Double Screw Extrusion Machine, Pipe Extrusion Line Pet Waste Bottle Recycling Pelletizing Machine, Pet Pelletizing Machine, Pet Flake Pelletizing Machine

Shandong Qufu Xingbang Heavy Equipment Co., Ltd. , http://www.chinaxingbangheavyindustry.com