Pressure, Mechanical

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Bulletin 836T Pressure Controls, Traditional Machine Tool

Factory Options

Factory-Set Pressure Controls

Ordering factory-set pressure controls

When a specific factory setting is requested, the specific terminal connections must be specified — e.g., N.O. or N.C. It must also be specified whether the contact operation is occurring on either increasing or decreasing pressure. For example:

Normally Closed (N.C.) contacts to open at⋆  psi increasing pressure and close at⋆  psi decreasing pressure.

—OR—

Normally Open (N.O.) contacts to close at⋆  psi increasing pressure and open at⋆  psi decreasing pressure.

If minimum differential is not critical and the inherent minimum differential satisfies the application, specify the factory setting as follows:

Normally Closed (N.C.) contacts to open at⋆  psi increasing pressure minimum differential.

—OR—

Normally Open (N.O.) contacts to close at⋆  psi increasing pressure minimum differential.

⋆ Specify psi (pounds per square inch) or, in. Hg vac (inches of mercury vacuum).

Quality analog test gauges♣  are used when applying requested factory settings to these rugged industrial grade pressure controls. (Gauges are calibrated and accuracy is traceable to the The National Institute of Standards and Technology.)

The actual requested setting is applied to the control by reading the set point directly from the test gauge being used. However, traceable gauge tolerance variance between source and user, and possible severe shock during shipping and installation, may contribute to the factory settings deviating slightly from the specified values. Slight recalibration can easily be accomplished upon final installation to meet specific requirements for the more demanding applications.

When installed, the controls will perform with a repeat accuracy as established in the paragraph entitled “Repeat Accuracy" (see Repeat Accuracy). Special service is available to factory-set controls on digital laboratory instruments, up to 600 psi, when required for more critical applications. An additional charge may be added for this service contingent upon setting tolerance and quantity. Please contact your local Rockwell Automation sales office or Allen-Bradley distributor.

♣ Per ANSI B40.1 Grade 2A (0.5% accuracy full scale), Grade 3A (0.25% accuracy full scale).

If not specified, setting tolerances will be as shown in the table below.

Pressure Range	Tolerance
30 in. Hg Vac.…0	+/- 1 in. Hg vac.
> 0…100 psi	+/- 1 psi
> 100…300 psi	+/- 2 psi
> 300…500 psi	+/- 5 psi
> 500…1000 psi	+/- 10 psi
> 1000…5000 psi	+/- 50 psi