home      |      sitemap      |      contact
Toll-Free: 800 346-4729
search our site
  Products & Services   »  Sanitary   »  Alfa Laval   »  Valves

761 Seat Valve

00001072
The Industry Standard
761 Seat Valve
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

103021412343

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

761-10761-30761-27
Reverse-Acting
761-47
Reverse-Acting
761-21761-23761-41761-43
<><>* Reverse-acting NA in long stroke
** For valves with control housings, add the following to dimension A:
Short stroke sizes: 1-3" (25.4-76.2mm), Add:19/16" (39.7mm)
Long stroke sizes: 1½ - 4" (38.1-101.6mm), Add: 3/4" (19.0mm)
761 Shut-Off and Divert Valves
Valve Size (Tube OD)A B C
Shut-Off Valves Divert & Reverse-Acting* Shut-Off Valves Divert Valves Reverse Acting Shut-Off Valves
Short Long Short Long
inch mm inch mm inch mm inch mm inch mm inch mm inch mm
761 Shut-Off and Divert Valves with Variable and Mid-Position “80S” Actuator
Valve Size (Tube OD)
A B C
Shut-Off Valves Divert Valves
Short Short
inch mm inch mm inch mm inch mm
2-inch18.25464.0023.56598.004.12105.003.5089.00
3-inch18.69475.0024.69627.005.00127.003.7595.00

Dimensions


<><>*Column “C” represents dimension “A” with the addition of a control housing module.
761-90 “Y” Body Shut-Off Valves
Valve Size (Tube OD) A B C
inch mm inch mm inch mm

<><>**For valves with control housings, add the following to dimension E: 1½-3" (38-76mm), add 19/16"(40mm)
Reverse-Acting Divert Valves
761-21 MRALL (Left Hand Tangential)
761-21 MRARR (Right Hand Tangential)
Valve Size A B C D E
inch mm inch mm inch mm inch mm inch mm
  

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
<><>* 4½" diameter actuator is standard on the 1"- 3" valves. A 6" diameter actuator is supplied with the 4" valve. A 4½" diameter actuator for the 4" valve is available upon request.
Type 10 (Normally-Open)
Shut-off valve holding pressures — 70 psi air pressure supplied to actuator
Short Stroke Actuator (Standard*) Long Stroke Actuator (Standard*) Type 15
Size Elastomer “TR” Stroke Length Elastomer “TR” Stroke Length 20PSI
1½-inch120 psi110 psi1"120 psi110 psi2"26
2½-inch35 psi20 psi1"60 psi50 psi2" 10
4-inch35 psi20 psi2"40 psi20 psi4"NA
<><>*4½" diameter actuator is standard on the 1"-3" valves. A 6" diameter actuator is supplied with the 4" valve. A 4½" diameter actuator for the 4" valve is available upon request.
Type 10 (Normally-Open)
Shut-off valve holding pressures — 90 psi air pressure supplied to actuator
Short Stroke Actuator (Standard*) Long Stroke Actuator (Standard*)
Size Elastomer “TR” Stroke Length Elastomer “TR” Stroke Length
<><>* 4½" diameter actuator is standard on the 1"-3" valves. A 6" diameter actuator is supplied with the 4" valve. The 6" diameter actuator is available, as a heavy duty option, for the 3" valve.
** On a standard actuator it takes 30 psi to offset the spring force when fully extended and 60 psi to fully compress the spring.
Type 20 (Normally-Closed)
Shut-off valve holding pressures (Standard)**
Short Stroke Actuator (Standard*) Long Stroke Actuator (Standard*) Type 25 Reverse Acting
Size Elastomer “TR” Stroke Length Elastomer “TR” Stroke Length psig
Type 20 (Normally-Closed)
Optional “HP” high pressure actuator. (6" diameter actuator)
Short Stroke Actuator (Standard*) Long Stroke Actuator (Standard*)
Size Elastomer “TR” Stroke Length Elastomer “TR” Stroke Length
2½-inch110 psi110 psi1"115 psi110 psi2"

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.

<><>Lubricated air is not required. Filtered air and a pressure regulator valve are required.
Valve Size Stroke (inch) Volume (cu. in.)
1½ - 3-inch short stroke114.80
4-inch short stroke HP250.00
Type 15 diaphragm19.00

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)


Valve Size Air to Product Pressure Ratio
Max RecommendedAir Assist
Max. Product Holding Pressure
1½-inch01:105200
2½-inch03:1020100
4-inch HP04:1025100

Technical data

Max. product pressure:depends on valve specifications and size (contact Alfa Laval)
Temperature range200° F to 284° F (EPDM)
Air pressure:60-80 PSI

Materials

 

Product wetted steel parts:Stainless steel AISI 316L
Finish:32 Ra Standard
Other steel parts:Stainless steel AISI 304
Plug stemBuna bonded or “TR”/"TR2" PTFE replaceable
Product wetted sealsBuna
Process connectionsTri-Clamp®

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.

 

 

For for more information about our products and services, contact us today!

 

 

 
HOME   |   ABOUT US   |   PRODUCTS AND SERVICES   |   OUR-MANUFACTURERS   |   CONTACT US
Copyright © 2017 Heerema Company
200 Sixth Avenue Hawthorne, NJ 07506   •   Phone: 973-423-0505   •   Outside NJ: 800-346-4729   •  Fax: 973-427-8672 
E-mail: sales@heeremacompany.com
web site design and development by powersolution.com:
also providing quality IT support and computer network services in New Jersey and beyond.


site admin