Accu-Flow Series 77, a Globe Type, Single Seated, Top Guided, Single Spring & Diaphragm Actuated, Throttling/On-Off type Pneumatic Control Valve.
Size Range: 15mm to 500mm
Pressure Rating: up to Class 600
Standard Features
- Top Guiding
It is a Top guided single seated control valve provides maximum support to ensure plug stability
- Trim
Quick change trim is provided as standard construction for easy maintenance as it is gasketed in to the valve body. Stellited trims are provided for high pressure & temperature service
- Tight Shut-Off
Class IV leakage is standard, optionally soft seating is provided for class VI leakage
Construction Features
- Body
Body wall thickness,hydrostatic test and end connections conform to ANSI B16.34 specifications. Body contours were developed through extensive laboratory testing to provide improved valve capacity, rangeability and stability
- Bonnet
Bolted bonnet has fully retained spiral wound pressure sealing gasket to assure a uniform gasketed joint and to prevent gasket blowout. Standard bonnet are forgings or high strength castings equivalent to valve body material
- Studs and Nuts
Alloy steel, ASTM A193 Grade B7 studs and ASTM A194 Grade 2H hex. Nut are standard for steel body construction. Other materials are available for services using body materials in corrosive applications and extremely high or low temperatures
- Trim
Standard material for valve plug, stem and seat ring is SS 304, 316. For guide bushings, heat treated SS 410 material is standard. Valve plug and seat ring are also available in stellited face and other materials on request
- Valve Plugs
Valve plugs are top guided and available with full size trims of quick opening, liner and % plug... standard reduced trim in liner, % plug, and metering pin contours. Valve plugs are precision manufactured and flow-tested for accurate flow characteristics and high capacity
- Seat-rings
The two piece construction of clamping retainer and seat ring provides economical quick change feature. The seat seals with a pressure sealing fully retained spiral wound gasket between seat and body. Compression is controlled to provide leak free seal over wide temperature differential
- Guide Bushing
Guide bushing is hardened, precision finished and passed in place. Length of bushing is a minimum one and one-half times the diameter of valve plug guide post. Full guide post engagement throughout valve plug travel provides excellent stability at high differential pressures and much longer service life
- Stuffing Box
Adjustable bolted stuffing box with spherical contact surfaces on hold-down plate provides excellent alignment
- Packing
Choice of spring loaded or compression packing. Standard material is Teflon®. Other materials are available to meet temperature requirements and to provide chemical compatibility with the fluid medium
- Actuators
Two types of standard actuators are available...
- Direct acting spring type actuator provides air to close action with direct acting valve plug, or air to open action with reverse acting valve plug. Reverse acting type actuator provides air to open action with direct acting valve plug, or air to close action with reverse acting valve plug.
- Stem Connector
Heavy duty anti-rotational split-type stem connector prevents stem from separating during valve operation. Its design maintains alignment of linkage on positioners and trips on limit switches.