Ball valve, Gate valve,Globe valve,Check valve,Plug valve,Butterfly valve,Valve parts

Catalogue:

Cast steel gate,globe,check valves.pdf

Brief introduction for the API gate valve.

The open-close part name is gate,that  this cast steel gate valve only can fully open or fully closed, they can not adjust the flow,the gate have two sealing face and the sealing face are wedge type,the gate also have two type according to interior structure,one is solid gate ,anther is flexible gate, the advantage of flexible gate is that it will not be stuck when being fastened between gate and seat. te maket of the flexible gate valve is bigger than other gate valves.


The kind of this cast steel gate valve.

We can divided into two types according to the  type of stem, one is non-rising stem gate valve, anther is rising stem gate valve,non-rising stem gate valve is mean that the screw of stem are in the body , we don't see the stem rising or decline when we opened and closed the gate valve, rising stem gate valve is mean that the screw of the stem are out of the body,we can see the stem rising or decline when we opened and closed the gate valve .

We also can divided into two types according to structure of the gate, one type is wedge gate valve, anther type is flat gate valve,wedge gate valve is mean the sealing face of the gate is wedge type(it have angle between them),flat gate valve is mean the sealing face of the gate is parallel type,wedge gate valve must rely on exogenic action to  mechanical seal,but flat gate valve can rely on  pressure of the medium to seal. so teh wedge gate valve have the bigger market than flat gate valve.


Advantage for the gate valve

All of the gate valve are full bore,so they have the very small fluid resistance and the sealing face is very resistant to shock and wear.

The flow of medium is not restricted when valves are installed in the pipeline.they have simple structure and have the short face to face.so the price is lower than ball valve.


Matters needing attention during installation

The workers must clean up the impurities in the piping and valves before the gate valve installed on the piping line.

The features of globe valve
Bolted Bonnet;Outside Screw and Yoke ;Rising stems;Metallic seating surfaces.
Body and Bonnet Connection
The body and bonnet of Class150~Class900 globe valves are usually bolted bonnet design .And the Class1500~Class2500 globe valves are usually of pressurized seal design.

Gasket of Cover Flange
Stainless steel + flexible graphite wounded gasket is used for Class 150 and Class 300 globe valve.Stainless steel + flexible graphite wounded gasket is used for Class ,and ring joint gasket is also optional for Class 600.Ring joint gasket is used for Class 900 globe valve.Pressurized seal design is used for Class 1500~Class 2500 globe valve.
Actuation
Hand wheel ,impact hand wheel and gear box is usually used for globle valve actuation.Chain wheel and electric acduator can be also used for globle valve actuation if being reguested by the customers.


Packing seal
Molded flexible graphite is used for packing material.PTFE or combined packing material can be also used if being requested by the customer.The internal surface of the stuffing box,of which area is contacted with the packing,is of excellent finish(Ra 3.2um).The stem surface ,contacting with the packing,should be rolled and pressed after being precisely machined,so as to reach to the high finish and compactness(Ra 0.8um)and ensure the reliable tightness of the stem area.
Belleville spring loaded packing impacting system
If being requested by the customer,the Belleville spring loaded packing impacting can be adopted for enhancing the durability and reliability of the packing seal.
Back seating design
All our globe valves have the back seating design.In most cases ,the carbon steek globe valve is fitted with a renewable back seat.For stainless steek globe valve,the back seat is machined directly in the bonnet or is machined after welding.When the globe valve is at fully open position,the sealing of the back seat can be very reliable.However,as per the requirement of API,it is not advisable to add or change packing by the mean of back seating when the valve is pressure containing.
Seat
For carbon steek globe valve,the seat is usually forged steel.The sealing surface of the seat is spray welded with hard alloy specified by the customer.Renewable threaded seat is used for NPS<10 globe valve,and welded on seat can be also optional if being requested by the customer.Welded on seat is used for NPS>12 carbon steel globe valves.For stainless steel globe valve,intergral seat is usually adopted,or to weld hard alloy directly intergrally.Threaded or welded on seat is also optional for stainless steel globe valve if being requested by the customer.
Stem design
The stem is of integral forged design.The minimum diameter of the stem shall per the standard requirement.
Stem nut
Usually,the stem nut is made of ASTM A439 D2.It is also can be made of copper ally if being requested by the customer.For large sized globe valve,rolling bearing is fitted at the two sides of stem nut in order to minimize the open and close torque of the globe valve.
Special globe valve
Besides the common globe valves,Chaoda Company also makes cryogenic globe valve,bellow sealed globe valve,Jacketed globe valve,etc.

OS&Y, Rising stem, Plug Disc
Bolted Bonnet, Threaded or welded seat ring
ASTM A216 WCB, A217 WC6, A351 CF8, A351 CF8M,
A351 CF3, A351 CF3M,A351 CN7M

Product Description:

OS&Y, Rising stem, Flexible Wedge
Bolted Bonnet,Threaded or welded seat ring
ASTM A216 WCB, A217 WC6, A351 CF8, A351 CF8M,
A351 CF3, A351 CF3M, A351 CN7M, A352 LCB

Standards Compliance:

Design and Manufacture: ANSI B16.34, API600 API6D, API603, BS1414
Face to face(end to end): ANSI B16.10, API6D
Flanged connection: 2"~24" to ANSI B16.5, 22", 26"~36" to MSS-SP-44 or to API605 on Request
Test and inspection: API598, API6D
Butt welded end: ANSI B16.5

A. Anti-friction ball thrust bearing:Reduces friction between mating parts to ensure smooth operation
B. Grub screw:Secures yoke nut in the bonnet
C. Grease nipple:Supplies lubricant to the mating parts

CLASS 150~1500 CAST STEEL GATE VALVE

CLASS 150~1500 CAST STEEL GATE VALVE