Skip to search Skip to main content Skip to navigation

Call us at 1-888-826-6342

We noticed you are from . Visit your local site for regional offers and live support.

Industrial Flow Switches - From 2 to 15 Feet/second


Item# FSW-40A

In stock

Lead Time (If not in stock): 5 weeks
Industrial Flow Switches - From 2 to 15 Feet/second FSW-40A FSW-40A
  • Rugged Industrial Design
  • Switch Point Adjustable While Unit Is Operating
  • 15 A SPDT Switch Directly Controls Pump
  • Mounts in Any Position

FSW-40A Model Options

View all models

Edit these specs to order a different model. Not all combinations are valid. Options compatible with previous selections will be in bold.

*Highlighted options are not compatible. Please select a different combination.

Velocity Range
Max Operating Pressure
Max Process Temperature
Process Connection Size
Wetted Materials
Media Type
Process Connection Type
Switch Rating and Type

  • Maximum Switching Current 15 A
  • Maximum Pressure 300
The FSW-40A and FSW-50 Series flow switches feature 15 A SPDT switches and an internal screw adjustment for in-line monitoring of switch points. Multiple drag disks provide incremental switch point adjustment. Their non-magnetic design makes these switches ideal for applications in which rust is a problem. The FSW-40A Series has a brass and stainless steel construction (optional 316 SS), while the FSW-50 Series comes in a plastic/316 SS construction.

The FSW-40A Series is ideal for machine-cutting oils and for sewage applications in which large objects are not caught on the drag disks. Installation “T” fittings are recommended for installing switches for 2' pipe size and below. For other pipe sizes, a “tee” fitting or weld coupling can be used.

Model No. Extra Disks
Pipe Sizes
Switch Point Adjustment Range (fps)
Low High
FSW-40A 1 1' 2.0 to 6.0 5.0 to 15.0
FSW-41A 2 1½ to 2½' 2.0 to 6.0 5.0 to 15.0
FSW-42A 3 3 to 10' 2.0 to 6.0 5.0 to 15.0
FSW-43A 3 10 to 48' 2.0 to 6.0 5.0 to 15.0
FSW-50 1 1' 3.3 to 5.3 7.4 to 11.5
FSW-51 1 1½ to 2½' 2.7 to 5.4 5.4 to 10.8
FSW-52 1 3 to 10' 2.0 to 4.0 4.0 to 8.0

Relay Switch: SPDT 15 A @ 125 or 250 Vac; 10,000,000 operations median
Nominal Sensitivity (% Flow Change to Activate Switch):
   10% @ upper end of range
   30% @ lower end of range
Pressure Drop: 1 to 3' pipe, less than 1 psi; 4' and above, negligible
Installation Fitting:
   FSW-40A Series: 1 NPT
   FSW-50 Series: 1¼ NPT
Max Pressure/Temperature:
   FSW-40A Series: 300 psig @ 82°C (180°F)
   FSW-50 Series: 100 psig @ 93°C (200°F)
Min Temperature: 4°C (40°F)

Wetted Parts:
FSW-40 Series: Brass, 300 to 304 SS, phosphor bronze and EPDM and cork rubber (other materials are brass body, Noryl® cover, 300 SS and plastic hardware); also available with 316 SS, FKM, and PTFE
FSW-50 Series: Polyphenylene sulfide, 316 SS, FKM; also available with polyphenylene sulfide, Hastelloy C and FKM construction
Electrical Cable Fitting: Water resistant for cable diameters 0.250 ±0.025'
   FSW-40A Series: 1.59 kg (3.5 lb)
   FSW-50 Series: 113 g (4.0 oz)
loading all models
loading all reviews
Rated 5 out of 5 by from works gretat Very good product for the marine industry. Works as planned.
Date published: 2018-06-25
Rated 5 out of 5 by from Thank you for the Product for our customer Product was well received by customer with a prompt delivery
Date published: 2024-04-29
  • y_2024, m_7, d_16, h_9
  • bvseo_bulk, prod_bvrr, vn_bulk_3.0.42
  • cp_1, bvpage1
  • co_hasreviews, tv_0, tr_2
  • loc_en_US, sid_FSW-40A, prod, sort_[SortEntry(order=HELPFULNESS, direction=DESCENDING), SortEntry(order=POSITIVE_FEEDBACK, direction=DESCENDING), SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_omega
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getReviews, 4ms
loading all QA

Is there a way I can purchase some more sail options / longer sails to use with this product?

Asked by: An WS
Thank you for your inquiry about the flow switches. If you are referring to spare parts, we have a Spare Parts Group that can advise on spare paddles, yet, it is limited to the pipe diameters available that flow switches can be installed. You may send an email to for your request.
Answered by: Application Engineer JC
Date published: 2023-02-08

Are there special considerations that need to be taken in terms of: 1. Installation orientation 2. Distance from elbows/spools/valves

Asked by: Sparky1234
It can be mounted in any position. The pipe on which the Flow Switch is installed should have 5 Diameters before the flow switch and 2 Diameters after to reduce turbulent flow.
Answered by: Application Eng HPO
Date published: 2022-11-30
  • y_2024, m_7, d_17, h_6CST
  • bvseo_bulk, prod_bvqa, vn_bulk_3.0.42
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_2
  • loc_en_US, sid_FSW-40A, prod, sort_[SortEntry(order=NUM_ANSWERS, direction=DESCENDING)]
  • clientName_omega
  • bvseo_sdk, java_sdk, bvseo-4.0.0
  • CLOUD, getContent, 34ms
Save Configuration