Tuesday, June 12, 2007

Check Valves

Check Valves

High Performance Non-Slam Nozzle Check Valve for highest economical demands.
Technical data:

  • Unique design for lowest pressure losses
  • Soft and metallic sealing
  • DN 50 – 1500
  • ANSI class 150 to 4500
  • -257°C to 537°C
  • Operating pressures up to p=434 bar
  • Face-to-face dimension acc. to ASME B 16.10
  • Flanged and welded bodies

Standard materials:

  • Body: Ductile cast iron, cast steel, stainless steel, duplex steel
  • Disc: Stainless steel, duplex steel
  • Spring: Stainless steel, Inconel
  • Seals: Buna-N, Viton-B, PTFE, metal

Typical applications:

  • Hot steam
  • Hot water
  • Petro-chemical applications
  • Hot gas applications
  • LPG, LNG-systems
  • Process for which elastomers and plastomers are not sufficient

Thursday, May 31, 2007

Check Valve

Check Valve

The non-return valves or check valves are used to block the reverse flow of oil or gas in a fluid power circuit. Additionally this valve may be used for pressure control or directional control. The check valve consists of a valve body with inlet and outlet ports and an internal movable member biased by the spring. The movable member can be a flapper or a plunger but most often in valves of hydraulic systems, it is a ball or poppet. They are built to provide free flow in one direction and a check in the other direction and prevent flow-back in hydraulic systems. Check valves are of several styles: swinging disc, ball, plunger, and poppet.

Check valves of the pilot-operated type are also popular. The connection at the bottom is connected to a remotely operated pilot valve, As in the ordinary check valve, free flow is permitted in one direction when the line pressure lifts the plunger thus opening the valve. The flow is checked in the opposite direction until pilot pressure is applied to the blind end of the plunger through the pilot connection. This causes the plunger to unseat the valve spool and oil is allowed to flow through the valve.

When system pressure at the check valve inlet port is high enough to overcome the biasing spring force on the poppet, the poppet is pushed off its seat allowing oil to flow through the valve. This is known as the check valve's free flow direction. When the fluid attempts reverse direction of flow, the spring pushes the poppet back on the seat to block flow through the valve. Check valves can be direct acting or pilot operated. A pilot operated version is used where the no-flow characteristic of the valve is desired only for a portion of the system cycle. A pilot operated check valve also allows free flow from its inlet port to its outlet port just as in an in-line check valve.

The design and construction of a check valve makes it one of the simplest fluid power components. Though simple, its use can make the system sophisticated. By application of check valves one can also design many sophisticated circuit diagrams where a constant flow can be maintained in both directions by using them in a bridge.

Wednesday, May 30, 2007

Pacific Valves

Pacific Pressure Seal Valves

Engineered for critical applications, Pacific Pressure Seal gate, globe and tilt-disc check valves are built to meet the requirements of ANSI B16.34. Typical uses of the Pressure Seal valve include fluid handling in oil and gas production facilities, flow control in power generating plants and process applications.
  • Gate Valves, Globe Valves, and Check Valves Pacific Valves

  • Class 600 - Class 2500

  • Sizes 2" - 24"

  • Flanged ends, and Butt-Weld ends

  • Flexible Wedge Gate

  • Parallel Disc Gate

  • Y-Globe

  • Lift Check

  • Tilting Disc Check

  • ANSI B16.34


Conventional Swing Check Valve.  Disc Closes through a long 90 degree arc  with reverse flow started. Shut off  characteristics are greatly improved with  addition of outside lever spring or weight  or air cushion chamber. SWING CHECK (SINGLE DISC)
Swing Check shut off depends on gravity (weight of disc) and reverse flow. The pivot point of the swing check is outside the periphery of the disc and, the greater the head, the greater the possibility that the fluid will flow back through the valve before the disc can shut off. To effect complete shut off, the disc of a swing check valve must travel through a 90 angle arc to the valve seat, as shown in Fig. 1. Without resistance to slow the disc's downward thrust, and encouraged by reverse flow, the shut off results in slamming and damaging water hammer. Use caution applying this type check valve where velocities exceed 3 FPS reverse flow and 30 psi.

Tuesday, May 29, 2007

Steel Valves

Steel Valves

---Crane Cast Steel Valves

Crane is the leading manufacturer of cast steel, globe and check valves. Typical applications for Crane cast steel valves include flow control and fluid handling for refining, oil and gas production, pulp and paper, waste water treatment and chemical processing.

  • Gate Valves, Globe Valves and Check Valves

  • Class 150 - Class 600 Steel Valves

  • Sizes 2" - 48"

  • Flanged ends and Butt-Weld ends

  • Bolted Bonnet and Pressure Seal Bonnet

  • Swing, Tilting Disc, Lift, and Stop Check

  • NACE and Special Trims (i.e., 316SS, Bronze, Monel)

  • API 600

Monday, May 28, 2007

Ball Valves

Ball Valves
Stockham Ball Valves

Stockham ball valves have gained wide acceptance with specifying engineers and contractors for commercial and industrial applications. Accurate machining and strict testing procedures ensure each user the quality that is built into every Stockham product. Stockham ball valves are routinely specified at chemical plants, petroleum refineries, pulp and paper mills, and for commercial building and general industrial service across the United States and around the world.
Scope of Line:400 psi Bronze Ball Valves
Two-piece design
Available in sizes from 1/4-inch to 3-inches (depending on Figure No.)
Threaded or solder joint ends

600 psi Bronze Ball Valves
Two-piece design
Available in sizes from 1/4-inch to 4-inches (depending on Figure No.)
Threaded or solder joint ends

1500/2000 CWP Carbon Steel Ball Valves
One-piece design
Available in sizes from 1/2-inch to 2-inches
Threaded ends

1500/2000 CWP Carbon Steel and Stainless Steel Ball Valves
Two-piece design
Available in sizes from 1/4-inch to 2-inches
Threaded ends

Friday, May 25, 2007

Plug Valve

Plug Valve

Plug Valve

Flange-Connection Lifting Plug Valve acc.to ANSI -129

Product DescriptionThe co has its ex-cellent mechanical processing equipment and modernized inspecion devices, the quality of its products are stable and credible to pass the ISO9001 international quality certificate, and obtained the qualified certificae awarde by National Mechanical Depart-mentlts also promising to API Approved Enterprises and CE Obtained Enterprises. Not only entitled the Excellent Products with New Science & Technology in Zhejiang Province are the ANSI type cutting sleeve rotating plug valves, but achie-ved the National Patent with patent no: 99227876.7, with many years quality certificate inspected by the county, provincial and national inspection departments.
Since establishment, the company has always innovated and created new products by science and technology to develop the quality products conforming to the standards of ISO, API&ANSI of America, BS of Britain, DIN of Germany, NF of French, JIS & JPI of Japan, GB&JB of China, Its main products are high temperature and high pressure gate Valve, globe valve, check valve, ball valve, plug valve, bellow globe valve, and plunger valve with inside nominas diameter of 1/2"-42"(DN15-DN1050), pressure lever of 150 LB-2500LB(1.0MPa-42.0MPa), and operating temperting temperature of -101~+680, The main materials of valve are A105. WCB304, 304, 304L, 316, 316L, 1Cr18Ni9Ti, 1Cr18-Ni12MO2Ti, etc. And can smelt and produce accrding to the clients special repuire-ments, The products are hot sold in all over the coutry and to over more than 10 coun Tries and areas, i.e. Mid-east, Southeast Asia, Europe and Unite States, widely used in the fieids of chemical industrial, fertilizer, metallurgy, pharmacy, electric power, as well as liquefied petroleum gas, etc, for complement valve of introducing equipment. The company will be in the consistent pursuit of the idea of "Quality Superior & Clients First"to Best service customers from anyplace with high quality and satisfying after-sale service.