Overview
The Dwyer FS-2-VANE is the replacement vane (paddle) assembly for the Dwyer Series FS-2 paddle flow switch. It is a service part, not a complete flow switch. The assembly is supplied as stacked stainless steel layers that are trimmed in the field to the blade length required for 1" through 8" pipe.
Use FS-2-VANE to restore a Series FS-2 switch whose vane has been trimmed too short for a new pipe size, damaged, or reassembled without its original screw and lockwasher. Dwyer specifically warns against substituting other screws or lockwashers, which may corrode and break, void the warranty, and cause severe damage to equipment downstream of the switch.
Specifications on this page are taken from the Dwyer Series FS-2 catalog page (Dwyer Instruments, LLC, rev. 11/2022) and the FS-2 Instruction Manual, Bulletin W-002 (FR# R5-443380-00 Rev. 1). Where the two differ the 2022 catalog page is used: it rates the enclosure NEMA 4 (IP64) where the 2014 manual lists IP64 only, and it adds the BSPT process connection and the optional conduit electrical connection. Verified August 2026.
Dwyer lists FS-2-VANE on the Series FS-2 product page under Accessories, described as a replacement vane assembly. It is a service part, not a complete flow switch.
Best For
- Re-blading a Series FS-2 switch moved to a larger pipe size
- Replacing a vane trimmed too short during commissioning
- Restoring a vane damaged by turbulence or debris
- Spare parts stock for boiler, chiller and cooling-line flow proving
Key Features
Direct Series FS-2 Service Part
Listed by Dwyer as the replacement vane assembly for the Series FS-2 paddle flow switch. It is not a complete flow switch and does not include the housing, bellow, snap switch or process connection.
Stainless Steel Vane
The Series FS-2 vane is specified as stainless steel, with the bellow in tin-bronze and the body in forged brass.
Field-Trimmed Layer Stack
Remove only the layers that are too long for the pipe and leave the shorter layers on to reinforce the vane. Resecure with the original screw and lockwasher, then lightly peen the screw end so it cannot back out.
Covers 1" Through 8" Pipe
Four blade lengths are covered: 1.34" (34 mm), 2.24" (57 mm), 3.46" (88 mm) and 6.57" (167 mm), spanning 1" through 8" pipe.
Trim Determines the Trip Point
Blade length and pipe size together set the actuation and deactuation flow rates. Confirm the correct blade length against the flow rate chart before trimming.
Do Not Substitute Hardware
Dwyer warns that replacing a lost screw or lockwasher with other parts, which may corrode and break, will void the warranty and may cause severe damage to equipment downstream of the switch.
Technical Specifications
| Model | FS-2-VANE |
|---|---|
| Part Type | Replacement vane assembly |
| Fits | Dwyer Series FS-2 paddle flow switch |
| Vane Material | Stainless steel |
| Blade Lengths Covered | 1.34" (34 mm), 2.24" (57 mm), 3.46" (88 mm), 6.57" (167 mm) |
| Pipe Size Range Served | 1" to 8" |
| Host Switch Temperature Limit | 230°F (110°C) |
| Host Switch Pressure Limit | 145 psig (10 bar) |
| Host Switch Service | Compatible liquids |
| Adjustment Method | Field-trimmed layer stack, secured by screw and lockwasher |
Blade Length and Flow Rate Reference
| Pipe Size | Blade Vane Length in (mm) Dim. X | Minimum Setting GPM (LPM) | Maximum Setting GPM (LPM) | ||
|---|---|---|---|---|---|
| Actuate | Deactuate | Actuate | Deactuate | ||
| 1" | 1.34 (34) | 4.0 (15.0) | 1.8 (6.7) | 8.8 (33.3) | 6.6 (25.0) |
| 1-1/4" | 1.34 (34) | 5.3 (20.0) | 2.6 (10.0) | 11.4 (43.3) | 8.4 (31.7) |
| 1-1/2" | 2.24 (57) | 7.0 (26.7) | 4.0 (15.0) | 14.5 (55.0) | 11.4 (43.3) |
| 2" | 2.24 (57) | 14.1 (53.3) | 9.7 (36.7) | 31.3 (118.3) | 22.5 (85.0) |
| 2-1/2" | 3.46 (88) | 18.5 (70.0) | 15.4 (58.3) | 35.2 (133.3) | 30.8 (116.7) |
| 3" | 3.46 (88) | 27.7 (105.0) | 25.1 (95.0) | 52.8 (200.0) | 46.2 (175.0) |
| 4" | 3.46 (88) | 59.4 (225.0) | 52.8 (200.0) | 123.3 (466.7) | 114.5 (433.3) |
| 5" | 6.57 (167) | 52.8 (200.0) | 39.6 (150.0) | 132.1 (500.0) | 123.3 (466.7) |
| 6" | 6.57 (167) | 75.7 (286.7) | 52.8 (200.0) | 154.1 (583.3) | 140.9 (533.3) |
| 8" | 6.57 (167) | 184.9 (700.0) | 158.5 (600.0) | 396.3 (1500.0) | 374.2 (1416.7) |
Replacement Procedure
- Isolate and drain the line, then remove the switch from the pipe.
- Remove the screw and lockwasher holding the vane layers together and keep both parts.
- Determine the blade length required for the pipe size from the flow rate chart.
- Remove only the layers that are too long; leave the shorter layers on to reinforce the vane.
- Resecure the vane with the original screw and lockwasher, then lightly peen the end of the screw with a hammer so it cannot back out.
- Reinstall with the arrow pointing in the direction of flow and confirm the vane has full range of motion without contacting the pipe wall, a bushing or a tee.
Documentation
Related Products
- Dwyer FS-21" male NPT process connection with cable gland and attached wire leads
- Dwyer FS-2-CND1" male NPT process connection with 1" NPT female conduit entry
- Dwyer FS-2-BSPT1" male BSPT process connection with cable gland and attached wire leads
- Dwyer FS-2-W81" male NPT process connection with cable gland and 8 ft attached wire leads
- Dwyer FS-2-BSPT-2M1" male BSPT process connection with cable gland and 2 m attached wire leads
Frequently Asked Questions
Is the Dwyer FS-2-VANE a complete flow switch?
No. Dwyer lists FS-2-VANE on the Series FS-2 product page under Accessories as a replacement vane assembly. It is the vane (paddle) service part only, and does not include the housing, bellow, snap switch or process connection. For a complete switch, order FS-2-CND, FS-2-BSPT, FS-2-W8 or FS-2-BSPT-2M.
Which Dwyer switches does FS-2-VANE fit?
It is the replacement vane assembly for the Dwyer Series FS-2 paddle flow switch, which covers all Series FS-2 part numbers regardless of process connection or electrical connection.
What blade length do I need?
Blade length follows pipe size: 1.34" (34 mm) for 1" and 1-1/4" pipe, 2.24" (57 mm) for 1-1/2" and 2", 3.46" (88 mm) for 2-1/2" through 4", and 6.57" (167 mm) for 5" through 8". The assembly is trimmed in the field to the length required.
Can I reuse the original screw and lockwasher?
Yes, and Dwyer requires it. If the screw or lockwasher is lost, do not substitute other parts; Dwyer states that substitutes may corrode and break, will void the warranty, and might cause severe damage to equipment downstream of the switch.
Does replacing the vane change the trip point?
Yes. Actuation and deactuation flow rates depend on both pipe size and blade length, so verify the trimmed length against the flow rate chart. After reassembly the adjustment bolt still sets the trip point between the published minimum and maximum settings.
Dwyer Instruments (DwyerOmega) Limited Warranty
DwyerOmega warrants its products to be free from defects in material and workmanship under normal use for one year, or such other period as specified in a product-specific warranty supplied with the product. No product-specific warranty period is published for the Series FS-2, so the standard one-year term applies. Full terms, including claim procedure and exclusions, are published in DwyerOmega's Warranty policy.
Series FS-2 specific conditions. The Series FS-2 is not field serviceable and should be returned if repair is needed; field repair should not be attempted and may void the warranty. Contact customer service for a return goods authorization number before shipping, and include a brief description of the problem plus any relevant application notes.
Adjusting the factory pre-set bolt may lead to switch malfunction and possibly void the warranty. If the vane screw or lockwasher is lost, do not substitute other parts, which may corrode and break; doing so will void the warranty and might cause severe damage to equipment located downstream of the switch.
- Product Type:
- Flow Switch Accessory
- Series:
- FS-2
- Vane Material:
- Stainless Steel
- Pipe Size Range:
- 1 to 8 in
- Accessory Type:
- Replacement Vane Assembly
- Compatible With:
- Dwyer Series FS-2
