761 Seat valve with 10 body.

Application

This air-operated seat valve features the positive action of either a short-stroke or long-stroke actuator. The 761 valve is ideal for high volume, sanitary liquid processing applications. Its heavy-duty construction and precision-molded bonnet gaskets ensure positive alignment under severe operating conditions. The 761 valve has a sanitary and flexible design allowing it to be used in a wide range of applications, e.g. as a stop valve with two or three ports or as divert valve with three to five ports.

Working principle

The valve is remote-controlled by means of compressed air. It has few and simple moveable parts which results in a very reliable valve.

Standard Design

The 761 Series valves are designed to deliver years of reliable performance. Rugged and long-lasting plastic stem bushings eliminate metal-to-metal galling. The stems are threaded to the actuator shaft, eliminating the coupling between the stem and the actuator, thereby ensuring proper alignment. The valve stem design requires only a single o-ring seal. And bushings at each end of the actuator cylinder support stem also ensure perfect alignment. The 761 series features a heavy-duty bonnet and body ferrule design that will stand up to years of pounding from hydraulic shock. Standard 32Ra finish on the ID.

Other valves in the same basic design:

• - Sanitary Remote controlled valve, type SRC
• - Aseptic Remote controlled valve, type ARC
• - Sanitary Long Stroke valve, type SRC-LS
• - Sanitary Manual valve, type SMO
• - Sanitary Manual valve, type SRC-BC
• - Sanitary Manual valve, type SMO-R, SMO-RA

Valve body combinations

10	30	21	41	23	43

Pressure drop/capacity diagrams

761 Short-Stroke Divert Valve		761 Short-Stroke Shut-Off Valve
Body Styles 21, 23, 41 & 43.		Body Styles 10 & 30.
Flow Pattern: B to A (Solid Curve), B to C (Broken Curve).		Flow Pattern: B to A (Solid Curve), A to B (Broken Curve) - Crossbodies Only.
In some cases, with low-viscosity liquids, the pressure drop in the long-stroke valve may actually be greater than the short-stroke valves.
		In some cases, with low-viscosity liquids, the pressure drop in the long-stroke valve may actually be greater than the short-stroke valves.
761 Long-Stroke Divert Valve		761 Long-Stroke Shut-Off Valves
Body Styles 10 & 30.		Body Styles 10 & 30.
Flow Pattern: B to A (Solid Curve), B to C (Broken Curve).		Flow Pattern: B to A (Solid Curve), A to B (Broken Curve) - Crossbodies Only
In some cases, with low viscosity liquids, the pressure drop in the long-stroke valve may actually be greater than the short-stroke valves.
		In some cases, with low-viscosity liquids, the pressure drop in the long-stroke valve may actually be greater than the short-stroke valves.

Dimensions

761-10	761-30	761-27 Reverse-Acting	761-47 Reverse-Acting
761-21	761-23	761-41	761-43

Dimensions

Actuator function

• - Pneumatic downward movement, spring return (NO)
• - Pneumatic upward movement, spring return (NC)
• - Pneumatic upward and downward movement (A/A),
• - Actuator for intermediate position of the valve plug as option

Actuator Air Supply Specifications

See chart below for minimum air pressure requirements.
Maximum air pressure is 100 psi (normal).
Air volume required is identified by the length of the stroke.

Additional Holding Pressure

Additional air supply must be relieved when product pressure is not present. Failure to do so will result in pressure damage to the seat. When using additional air loading it should exceed the minimum required by no more that 3 to 5 psig.

Example: A customer has an application for a 3" valve that is required to hold 70 psi product pressure with an elastomer (Buna). The valve without an air assist will hold 40 psi. An additional holding force to overcome 30 psi (70 psi-40 psi) is needed. Since the ratio is 5:10 (air-to-product pressure ratio) a 15 psi air assist is needed.

Note: Since it takes 60 psi to fully stroke the valve without air assist, it will take 75 psi to open the example. (60 psi+15 psi)

Technical data

Materials

Options

Equipment

• - Process connections, weld, bevel seat
• - Control and indication (Control Top or ThinkTop®)
• - High pressure actuator for 2½" and 3" size
• - High pressure actuator for 2½" and 3" size
• - Three Position Actuator (80)
• - 20 Ra or 15 Ra ID surface finish
• - Long stroke actuator

Material grades

• - Molded elastomers of EPDM, SFY, or PTFE
• - O-rings and seals of EPDM or SFY (Flouroelastomer)

Ordering

Please state the following when ordering:

• - Size.
• - Connections
• - Valve body combination.
• - Actuator function, NC, NO or A/A
• - Options.