Laing Watkins E-5 SilentFlo 5000 - Spa Circulation Filtration Pump
Laing Watkins E-5 SilentFlo 5000 - Spa Circulation Filtration Pump is backordered and will ship as soon as it is back in stock.
Delivery and Shipping
Delivery and Shipping
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E-5 SilentFlo Laing ITT Pump used in Hot Spring, Sundance, Caldera, Watkins, Tiger River and more.
Note, you can also replace with the newer, more-efficient E10 here.
It also suits many other brand spas and hot tubs. Has 3/4" barb fittings. Magnetic drive. The Laing E5 pump replaces single speed 5000 and two speed 5002 circulation pumps.
- All Caldera Spas Circulation Pumps from 2002 - Current
- SM303
- Hot Springs Models from 1986-2009
- Tiger River Models from 1986-2009 MFG #74416
- Silent Flow Circ Pump E5-NSHN2W14 ,E5-NSHNNN3W14
- LTI PN : 73379, Watkins PN: 301393
- 73379, 74427, 6641
- SilentFlo 5000
- SilentFlo 5002
- See longer list below.
The new E5 replaces the Watkins SilentFlo® 5000 and all previous circulation pumps on all Hot Spring, Tiger River and Limelight spa models from 1986 to 2018.
The suction is 1-11/16" from the bottom of the pump and the discharge is 4-1/4" from the bottom.
Volts: 120/240
Hz: 50/60
Watts: 40
Intake: 3/4" barb
Discharge: 3/4" barb
Model: E5-NCHNNNN3W-10
Replaces: PN: 34378, 73491, A-05-280-502, LTI P/N: 7060,70813, 73588, 73989, 73588, 37949, 10-0102 , 611452 , 733886902600 , 733886940602 , 74427 , 900300632 , 9026 , 9406 , E5-NSHNNN3W , LAISM303NH3/4 , LAISM303NHT , SM303NH-75 , SM303NHT, 10-0102-K, 10-0102 , 611452 , 733886902600 , 733886940602 , 74427 , 9026 , 9406 , E5-NSHNNN3W , LAISM303NH3/4 , LAISM303NHT , SM303NH-75 , SM303NHT, Watkins 74427, Watkins 74416, Hot Springs 74427, Watkins 74416, Caldera 74427, Caldera 74416, Tiger River 74427
In plumbing, named sizes are not the actual measurements. A pipe called “50mm” or “2"” does not measure 50 mm across. Instead, it follows nominal sizing, an internationally-standardised naming system.
Use the Outside Diameter (OD) to check your pipe against fittings. Below is a quick reference for common spa & pool pipe sizes:
| Imperial Name | Metric Name | Pipe Diameter (OD) |
|---|---|---|
| 1" | 25 mm | ~33.4–33.7 mm |
| 1.5" | 40 mm | ~48.1–48.4 mm |
| 2" | 50 mm | ~60.2–60.5 mm |
| 2.5" | 65 mm | ~75.2–75.5 mm |
These are nominal sizes and are designed to fit matching fittings — not to measure exactly what their name suggests.
Understanding Plumbing Sizes & Nominal Measurements
Plumbing sizes can be confusing. PVC and many other pipe systems use nominal sizes—the size is a name, not the exact measured dimension. This convention is used across most pool and spa systems so that pipes and fittings remain compatible.
Why pipe sizes don’t match the measurements
The Nominal Pipe Size (NPS) system standardises pipe dimensions so that pipes, fittings, valves, and accessories interoperate. Plumbers work with these nominal names every day, but DIYers can be tripped up if they try to match by a tape-measure alone.
How to Measure Pipe Correctly
-
Pipe size is identified by:
- The pipe’s Outside Diameter (OD).
- The fitting’s Inside Diameter (ID) (socket opening).
- Pipe Class / Schedule (e.g., Class 9, 12, 18 or Sch 40) relates to wall thickness and therefore the Internal Diameter (ID) and pressure rating.
- The outside diameter of a fitting is not useful (wall thickness varies by manufacturer).
PVC Pressure Pipe AS/NZ 1477 Dimensions1:
Common nominal sizes with typical outside diameters and indicative inside diameters by class.
| Imperial Name | Metric Name | Outside Diameter (OD) | Class 9 IDº | Class 12 IDº | Class 18 IDº |
|---|---|---|---|---|---|
| 1/2" | 15 mm | ~21.2–21.5 mm | 18.3 mm | 17.8 mm | |
| 3/4" | 20 mm | ~26.6–26.9 mm | 23.7 mm | 22.4 mm | |
| 1" | 25 mm | ~33.4–33.7 mm | 30.5 mm | 29.8 mm | 28.1 mm |
| 32 mm | ~42.1–42.4 mm | 38.5 mm | 37.5 mm | 35.4 mm | |
| 1.5" | 40 mm | ~48.1–48.4 mm | 45.2 mm | 44.1 mm | 42.8 mm |
| 2" | 50 mm | ~60.2–60.5 mm | 55.2 mm | 53.7 mm | 50.5 mm |
| 65 mm | ~75.2–75.5 mm | 68.9 mm | 67.0 mm | 63.2 mm | |
| 2.5" | ~73 mm |
- º Internal diameters vary slightly by manufacturer and class.
- 1 Not all pool/spa fittings match these dimensions exactly. Some do not follow Australian or international standards. Chinese spas may use proprietary fittings.
Hose & Tube Dimensions
Common flexible hose sizes used in pool/spa systems (approximate IDs).
| Imperial Name | Metric Name | Inside Diameter (ID) |
|---|---|---|
| 3/8" | 9–10 mm | ~9 mm |
| 3/4" | 19 mm | ~19 mm |
BSP – British Standard Pipe Thread Sizes
BSP thread names are also nominal. The thread OD will not equal the nominal name.
| BSP Thread Size Naming | Outside Diameter (mm / inch) | TPI |
|---|---|---|
| 1/16" BSP | 7.7 mm / 0.304" | 28 |
| 1/8" BSP | 9.7 mm / 0.383" | 28 |
| 1/4" BSP | 13.16 mm / 0.518" | 19 |
| 3/8" BSP | 16.66 mm / 0.656" | 19 |
| 1/2" BSP / 15 mm | 20.99 mm / 0.825" | 14 |
| 5/8" BSP | 22.99 mm / 0.902" | 14 |
| 3/4" BSP / 20 mm | 26.44 mm / 1.041" | 14 |
| 7/8" BSP | 30.20 mm / 1.189" | 14 |
| 1" BSP / 25 mm | 33.25 mm / 1.309" | 11 |
| 1-1/4" BSP | 41.91 mm / 1.650" | 11 |
| 1-1/2" BSP / 40 mm | 47.80 mm / 1.882" | 11 |
| 2" BSP / 50 mm | 59.61 mm / 2.347" | 11 |
| 2-1/4" BSP | 65.71 mm / 2.587" | 11 |
| 2-1/2" BSP | 75.18 mm / 2.960" | 11 |
| 3" BSP | 87.88 mm / 3.460" | 11 |
| 4" BSP | 113.03 mm / 4.450" | 11 |
| 5" BSP | 138.43 mm / 5.450" | 11 |
| 6" BSP | 163.83 mm / 6.450" | 11 |
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