Alfa Laval A49-42 Vacuum Breaker

Alfa Laval's A49-42 manual vacuum breakers provide relief from vacuum conditions in process lines. When used as a vacuum breaker, the A49-42 guards against siphoning and backflow, reducing the risk of product contamination and quality issues as well as protecting sensitive equipment. The A49-42 can also be "flipped" and used as an air eliminator, great for venting entrapped air on the suction side of a pump. The valve's quick clamp-style assembly and simple design allows for the working parts for be rotated, converting the valve from a vacuum breaker to an air eliminator.

The A49-42 vacuum breaker is constructed of sanitary stainless steel, and is 3-A compliant for manual cleaning, making it a great choice for a variety of hygienic applications.

B44MP is available in the following sizes: 1.5 inch and 2 inch.

  • Available in 1.5 inch and 2 inch
  • Line pressure positions the stem and o-ring
  • Valve is positioned at the high point of the piping
  • Can be used as an air eliminator on suction side of pump
  • Not clean-in-place (CIP) capable, must be clean-out-of-place (COP)
  • 3-A compliant

A49-42 valves are used at the high point of a high-temperature short-time (HTST) pasteurization system to prevent contamination of pasteurized product due to backflow. The sealing plug of the valve can also be reversed for use as an air eliminator for the suction side of a pump and similar applications.

Models B44MP and A49-42 vacuum breakers are designed for line service only. They are not intended for use on tanks or vessels.


The A49-42's plug and o-ring assembly provide a seal against the base of the valve when the process line experiences normal, positive pressure. During vacuum conditions, the plug and o-ring drop down, allowing air into the system and eliminating the vacuum.

Standard Design

Model A49-42 is available in 1.5 or 2 inch Tri-Clamp connections. It uses a teflon plug and o-ring design to provide a seal during normal processing. The plug configuration is reversible for use as an air eliminator. The valve features a small bell hood on top to direct any product blow-by down towards the floor.

Product Wetted Parts316
O-ringBuna, other options available
Dimensional Data

Overall Height: 1.625 inch

Product Literature

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