Skip Content


1 MNPT — General Purpose Switch, —

  • Item # 2RUL3
  • My Part #
  • Mfr. Model # FS251
  • Catalog Page # 2736
  • UNSPSC # 39121538
General Purpose Flow Switch,NEMA1 close

Using 360° Viewing:

  1. Rotate: Use top-to-bottom, side-to-side by use of mouse arrow.
  2. Zoom In: Double click on image.
  3. Zoom Out/Reset: Put photo at full zoom & then double click.

CAD Downloads

Web Price $137.00 / each
Activate Now

to save with

Select AdvantageSM

Please sign in or register to access lists

Please sign in or register to access Quote

Get Free Standard Shipping
Jump to:
  • Shipping Weight 1.99 lbs.
Country of Origin Mexico Country of Origin is subject to change.
Note: Product availability is real-time updated and adjusted continuously. The product will be reserved for you when you complete your order. More

Product Details

Featuring a sensitivity adjusting screw to ease flow adjustments, this MCDONNELL & MILLER general-purpose switch has an In-line configuration that eliminates the need for a pipe tee. Switch is ideal for general-purpose applications requiring low-flow rate sensitivity and is suitable for use in starting and stopping electrically-operated equipment.

View More

Technical Specs

  • Item General Purpose Switch
  • Min. Flow Rate (GPM) 5.8
  • Max. Flow GPM 131
  • Connection Size (In.) 1 MNPT
  • Switch Enclosure NEMA 1
  • Min. Ambient Temp. (F) 32
  • Min. Fluid Temp. (F) 32
  • Max. Fluid Temp. (F) 250
  • Max. Pressure (PSI) 160
  • Operating Velocity Range (FPM) 130 to 280
  • Switch Type Single Pole Double Throw Snap Switch
  • Contact Rating 7.4A @ 120 VAC - Full Load, 120 VA @ 120 or 240 VAC - Pilot Duty
  • Body Material Brass
  • Material of Construction Brass, SS, EPDM
  • Wetted Materials Brass, Stainless Steel, EPDM
  • Max. Operating Velocity (FPM) 600
  • Voltage 120/240
  • For Use With Water Systems
  • Application Signal Lights, Alarms, Motors, Automatic Burners and Metering Devices
How can we improve our Technical Specifications?

Compliance and Restrictions

Replacement Parts

Alternate Products

Alternate Products may not be identical in style or function to original selection. Please compare below for more information.

Related Products

Customer Reviews

1 MNPT General Purpose Switch, is rated 4.7 out of 5 by 3.
Rated 5 out of 5 by from Work great, the only manufacture we use at the hospital and our Account Manager has been anle to get us the best price we have found.
Date published: 2013-04-25
  • y_2017, m_12, d_14, h_19
  • bvseo_bulk, prod_bvrr, vn_bulk_2.0.3
  • cp_1, bvpage1
  • co_hasreviews, tv_2, tr_1
  • loc_en_US, sid_2RUL3, prod, sort_[SortEntry(order=SUBMISSION_TIME, direction=DESCENDING), SortEntry(order=FEATURED, direction=DESCENDING)]
  • clientName_grainger

Product Reviews Disclaimer:
Grainger is neither responsible for, nor does it endorse, the content of any product review or statement posted. Any statements posted constitute the statements of the poster and are not the statements of Grainger. The statements posted by Grainger employees with the Grainger employee badge represent the views of such employees and are not the statements of Grainger. Grainger makes no representations as to the appropriateness, accuracy, completeness, correctness, currentness, suitability, or validity of any product review or statements posted, including those posted by employees with the Grainger employee badge, and is not liable for any losses, injuries or damages which may result from any such product review or statements. Use of any linked web site provided in a product review or post is at the user's own risk.