Rising Stem Cast Globe Valve BB Bonnet Flange Ends Buttwelding Ends
APPLICATION & FUNCTION
Globe valves are primarily used as control valves where throttling or both throttling and shut-off are required. Globe valves can also be used for on-off service; however, because of the design, a pressure drop becomes inherent. This is generally confined to on-off applications where the valve is normally closed and pressure drop is not important when the valve is open. Normal applications will find the globe valve with the flow and
pressure under the disc. cast steel globe valves are commonly made in outside screw and yoke designs with full ports (including seat ring) and heavy-duty, conical plug type discs.
BODY & BONNET
The body is full ported and spherical in form. The design utilizes large radiuses which allow for the stresses, flow resistance and turbulence to be kept to a minimum. Valve bonnets are equipped with a backseat bushing.
The valve is normally supplied with the conical plug type disc. The disc rotates freely on the stem and incorporates a differential angle from that on the seat ring. This design provides the maximum assurance of shut off, is less likely to stick in the body seat, and is considered the simplest design for field repair. The disc is held onto the stem utilizing the disc nut and a split-ring disc retainer on 2”–4” in pressure classes 150 and 300.
Larger sizes as well as pressure classes 600 and higher utilize the disc nut and a button head design which is integral with the stem. Bottom guided discs are available.
Seat rings are designed to greatly reduce and/or prevent any turbulence and avoid damages due to corrosion. The seat rings are forged or rolled in one piece and then seal welded and overlaid, if required. After welding and all required heat treating, the seat ring faces are machined, thoroughly cleaned and inspected before leaving for assembly.
As standard, all stems are rotating and rising; however, a non-rotating design is available when specified by the customer. The accuracy in the dimensions and finishes assure a long life with a perfect tightness in the packing area, resulting in lower fugitive emissions. All of our stems are designed with integral backseat features which provide an ultimate seal during packing changes.
The depth of the stuffing box allows for a sufficient amount of packing, which makes the stem seal. GWC’s standard packing arrangement and stuffing box design meets<100 ppm fugitive emission requirements. If specified in the purchase order, lantern rings and/or grease injectors can be
The stem packing is designed and arranged to ensure a maximum seal along the stem during operation or while at position, thus allowing for a greater reduction in fugitive emissions. Our packings are of nonasbestos types.
Valve can supply any style of packing required by the customer.
The packing gland design is a two-piece self-aligning type. The packing gland has a spherical head that rides within the spherical joint of the gland flange. The packing gland has a shoulder, which restricts the complete entry into the stuffing box bore. This particular design assures a straight compression of the packing as the gland eyebolts are being equally adjusted, without injuring the stem.
The stem nuts on standard rising stem globe valves are threaded into the top of the yoke where they are secured with a ack weld.
Handwheels are designed with a comfortable grip for easy operation. Our valves are also available with gearing, motor actuators or cylinder actuators for the more demanding services.
BOLTS AND NUTS
For normal service conditions, ASTM A194 Class 2H and ASTM A193 Grade B7 nuts and stud bolts are furnished. If specified for high temperature service conditions, ASTM A194 Class 4 and ASTM A193 Grade B16 nuts and stud bolts are furnished. Standard bolting furnished for our stainless steel valves consists of ASTM A194 Class 8 and ASTM A193 Grade B8 nuts and stud bolts.
Valve can supply any bolting as requested by the customer.
Our standard production covers valves with:
• Flange ends with Raised Face (RF), Flat Face (FF) or Ring Type Joint (RTJ) that conform to B16.5.
• Butt-welding ends (BW) that conform to B16.25.
• All face-to-face/end-to-end dimensions conform to B16.10.
• Other special end connections are supplied according to customer’s requirements.
Accessories such as gear operators, actuators, bypasses, locking devices, chainwheels, extended stems and bonnets for cryogenic service and many others are available to meet the customers requirements.
Technical parameters and characteristics:
||Casting globe valve
||-29℃～593℃(the range of service temperature may vary for different materials)
||A216 WCB,WCC; A217 WC6,WC9,C5,C12,C12A,CA15; A351 CF8,CF8M,CF3,CF3M,CF8C,CN3MN,CK3MCUN,CN7M;A352 LCB,LCC; A494 CW-6MC,CU5MCuC,M35-1; A890 4A(CD3MN),5A(CE3MN),6A(CD3MWCuN); ASME B 148 C95800,C95500, etc.
||BS 1873 ,ASME B16.34,GB/T 12235,GB/T 12224
||ASME B16.10,GB/T 12221
||ASME B16.5,ASME B16.25,GB/T 9113,GB/T 12224
||API 598,ISO 5208,GB/T 26480,GB/T 13927
||Elevating hand wheel, non-elevating hand wheel, bevel gear, motor drive unit, pneumatic drive unit
||For application in fields such as electric power industry, petroleum refining, petrochemical engineering, offshore oil, tap water engineering in urban construction, chemical engineering, etc.
|Other remarks 1
||The sealing faces of valve seat and valve clack are build-up welded with hard alloy to improve the erosion resistance and extend the service life of valve.
|Other remarks 2
||The friction between sealing faces is smaller during opening and closing, facilitating a longer service life.
|Other remarks 3
||The valve clack is of taper, needle, ball and parabola types, and can be used to adjust the flow rate.
|Other remarks 4
||SS+ graphite or metallic seal or pressure self-sealing is adopted between valve body and bonnet for reliable sealing
|Other remarks 5
||Rising stem structure, making the valve switch position be clear at a glance
|Other remarks 6
||The valve stem thread will not come into contact with the medium, so the corrosion of medium to the thread is reduced.
|Other remarks 7
||A certain clearance is provided between valve clack and valve stem. You may adjust it by yourself. The sealing is reliable.
|Other remarks 8
||The valve clack can be machined into parabola, spherical, needle shapes, etc. according to the requirement of customer. It can be used for adjustment (rough adjustment) on pipeline.
|Other remarks 9
||Short stroke is suitable for application at positions subject to frequent opening.
|Other remarks 10
||Through improving the structural design and selecting reasonable packing structure and qualified packing supplier, the valves can meet the Class A sealing test requirements of ISO 15848 FE.