💧 Flow Switch, Harwil Q12DS, 1/2″ Male Pipe Thread, 2A
Made by Harwil, manufacturer part number Q12DS501.54SNO1. If your old part carries one of the cross-reference numbers further down, this is listed as its alternative.
📏 Specifications
| Specification | Value |
|---|---|
| Brand | Harwil |
| Manufacturer part number | Q12DS501.54SNO1 |
| Model | Q-12DS |
| Plumbing Connection Type | Male Pipe Thread (mpt) |
| Plumbing Connection Size | 1/2″ |
| Flow Switch Application | Multiple |
| Flow Switch Amperage | 2A |
| Catalog description | Flow Switch, Harwil Q12DS, 1/2″ Male Pipe Thread, 2A |
🔄 Cross-reference part numbers
These part numbers are listed as alternatives for this part.
| Brand | Part number |
|---|---|
| Harwil | Q-12DS50/1/4S/NO/1 |
Please use 26-578-1101 which includes necessary fittings for installation.
Harwil Q12DS Flow Switch 1/2" NPT
2 amp pilot duty switches on at 10 gpm and switches off at 8 gpm. ABS body, stainless spring arm.
Stationary arm measurements:
- 2" Distance between end of the arm and bottom of the threads
- 2-5/8" Distance between end of the arm and top of the threads
🔧 Parts and fittings for this
| Part | Our part number | Availability | Price | ||
|---|---|---|---|---|---|
![]() |
Flow Switch, Harwil Q8DS, 1"mpt, 25A, w/Drag Strip | Q8DS/A/10502 | 17 in stock | $99.04 | Add to cart |
![]() |
Reducer Bushing Fitting 437-251 – 2"SPG x 1-1/2"S | 437-251 | 779 in stock | $5.02 | Add to cart |
![]() |
Generic PTFE Teflon/Plumbers Thread Seal Tape A05-0265 | A05-0265 | 214 in stock | $1.27 | Add to cart |
![]() |
Silicone, DOW 732, 3oz Tube, Clear | DC-732-CLR-3 | 186 in stock | $17.88 | Add to cart |
![]() |
Lasco Reducer Bushing 438-101 – 3/4" SPG x 1/2" Slip | 438-101 | 238 in stock | $0.47 | Add to cart |
![]() |
Lasco Fitting 401-007 | 401-007 | 66 in stock | $2.89 | Add to cart |











