The Valtek Valves Sizing & Selection Manual is a comprehensive, easy-to-follow reference guide for determining the proper control valve for a particular application. The material follows the sequential order of the typical Valtek Valves quote sheet.
This introduction discusses general information about control valve sizing. It also outlines the basic control valve parameters which must be known for correct sizing.
THE VALTEK FLOWSERVE CONTROL VALVE
A Valtek Flowserve Valve is a final control element used in instrumentation systems to regulate the flow, pressure or temperature of liquids and gases in process systems.
A control valve is different from other valves in that it has a power positioning actuator for moving the closure mechanism in response to an external signal. The actuator’s energy source is usually provided from an independent source.
Section 1: Valtek Introduction
Valtek Mark One
Mark One globe-style control valves feature a standard cast carbon steel or stainless steel globe body, top entry trim with a characterized plug contour, high thrust double-acting piston actuator, four-way positioner, and fail-safe return spring. In addition to the carbon and stainless steel construction, Mark One bodies can be furnished in various grades of chrome-moly, alloy 20, Hastelloy “B” and “C”, Monel, Inconel, titanium, bronze, nickel, and other castable materials.
The Mark One is available in sizes ranging from 1/2 through 42-inch, and in ANSI Pressure Classes from 150 through 4500. Body styles include standard globe, globe with expanded outlets (Mark One-X), angle and three-way configurations. A variety of end connections is also available, including raised face, RTJ (ring-type joint), socketweld, buttweld, NPT (National Pipe Threads) and Grayloc. This versatility makes the globe design the most widely used of all control valve types.
Valtek Mark Two
Mark Two control valves are similar to Mark One globe style valves except that the body is fabricated from barstock. It is typically available in sizes from 1/2 through 2-inch and Classes from 150 through 2500. Special designs are also available for body sizes up to 6-inch with special applications to 15,000 psi.
Valdisk is a high-performance eccentric disk control valve with quarter-turn action. It utilizes an elastomeric or metal seat for tight shutoff. Valdisk features a flange less wafer body that fits between raised-face line flanges.
ShearStream is a high-performance ball valve designed to overcome the problems of harsh, particle entrained processes. Its high 300 to 1 rangeability, or turn down ratio, also makes ShearStream an ideal control valve for use in high temperature water and steam applications. It is available in sizes 1-inch through 12-inch and ANSI Pressure Classes 150, 300 and 600. Class IV and VI shutoff are achieved with Valtek’s unique FlexLoc TM metal seal and soft seal design, respectively.
ShearStream’s V-notch ball design reduces clogging and improves shearing action, making it an ideal control valve for particle entrained processes.The one-piece body design overcomes many long standing challenges faced by traditional ball valves: piping forces that unevenly load the seat, low rangeability due to limited orifice characterization, and unsatisfactory shutoff capabilities. Available body materials include 316 stainless steel and carbon steel. Ball materials available include 317 stainless steel with either hard chrome or Stellite facing.
Valtek MegaStream, ChannelStream and Tiger-Tooth
MegaStream, ChannelStream and Tiger-Tooth control valves use special trim enclosed in the standard Mark One body to eliminate problems associated with high pressure drops.MegaStream minimizes the aerodynamic noise associated with gas services. Channel Stream eliminates cavitation and vibration in liquid services.Tiger-Tooth is used in liquid services to eliminate cavitation and in gaseous applications when the required noise attenuation exceeds 20 dB. All three valves use the same materials of construction as the Mark One.
These special trims act to eliminate noise and damaging cavitation which would otherwise severely limit service life of the valve, cause premature mechanical failure of the component parts or prevent personnel from working near the valve.
Valtek also offers special service control valves which are designed for a specific application where standard control valves are not particularly suited or easily adapted.
Tek-Check check valves are often used with reciprocating and centrifugal pumps to provide directional flow control.The body and seat ring are both interchangeable with the Mark One. Tek-Check materials of construction are the same as the Mark One.
Valtek Mark Six
Mark Six cryogenic valves are specially designed for use in cryogenic air separation columns where all equipment is sealed and insulated in the cold box.Access to the trim is through the valve bonnet.Bodies are available in bronze and various grades of stainless steel.
Valtek Mark Eight
Mark Eight Y-pattern valves offer a greater capacity per valve size than do standard globe valves, while at the same time retaining the advantages of the globe valve configuration. Materials of construction are identical to the Mark One.
Section 2: Valtek Models and Specifications
- Valtek Sizing Nomenclature
- Velocity Calculation
- Liquid Sizing
- Gas Sizing
- Fluid Correlation Constants
- Pipe Data
Section 15: Valtek Severe Service Data Tables
Section 18: Handwheels
Section 19: Valtek Accessories
- Air Filters
- Valtek Transducers
- Volume Boosters
- Lock-up Systems
- Air Spring
- Heavy-duty Springs
- Oversized Actuators
- Special Tubing and Fittings
- Special O-rings
- Position Indicators
- Proximity Switches
- Speed Control Valves
- Switching Valves
Section 23: Glossary
Section 24: Hazardous Location Certification For Electrical Equipment