Astralpool ZX Filter Lid with Handles & Locking Ring
Astralpool ZX Filter Lid with Handles & Locking Ring is backordered and will ship as soon as it is back in stock.
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Astralpool ZX Filter Lid with Handles & Locking Ring
Astralpool ZX Filter Lid with Handles & Locking Ring is backordered and will ship as soon as it is back in stock.
Astralpool
Genuine Astralpool ZX, Zodiac ZCF, Filtrite CF Cartridge Filter Lid with Locking Ring – SP 7820502.
Replace your cracked or leaking filter lid with this genuine AstralPool ZX cartridge filter lid assembly, supplied complete with new locking ring, air bleed valve, and air bleed O-ring. Ensure you order correctly, as these have been re-branded, and came in various colours.
Fast Australia-wide shipping or in-store pickup available.
This lid suits a wide range of Astralpool, Hurlcon, Leisure Pools Smart, Filtrite CF and other re-branded cartridge filters. Manufactured from heavy-duty UV-stabilised plastic for Australian conditions.
What’s Included
- Complete ZX filter lid top
- New locking ring
- Air bleed assembly
- Air bleed O-ring
Note: These lids have previously been grey, beige and black. Current production is black only.
Compatible Models
- Astralpool ZX Series: ZX50 / ZX 50, ZX75 / ZX 75, ZX100 / ZX 100, ZX150 / ZX 150, ZX200 / ZX 200, ZX250 / ZX 250, ZX310 / ZX 310
- Leisure Pools Smart: Smart 350, Smart 450, Smart 550
- SpaPro: X50 / X 50, X100 / X 100, X150 / X 150, X200 / X 200
- Filtrite CF: CF50 / CF 50, CF75 / CF 75, CF100 / CF 100, CF150 / CF 150, CF200 / CF 200, CF250 / CF 250
- WWDG CF: CF100 / CF 100, CF150 / CF 150, CF200 / CF 200
- Astral IX Inline Leaf Canisters
- Some older Hurlcon cartridge filters
Part Numbers
SP7820502 / SP 7820502 / 7820502 / APA302685 / APA_302-685
Important
This listing is for the lid assembly only. If you require the large tank body O-ring, you can find it here: ZX Filter Tank O-Ring
Why Replace Your Filter Lid?
- Fix air leaks causing pump cavitation
- Restore correct filter pressure
- Stop water leaks around the locking ring
- Prevent unsafe pressurised operation
Manufacturer Catalogues, Diagrams & Part Numbers
Need exploded views, spare part numbers, product numbers, diagrams, or more product information? See the manufacturer catalogues: AstralPool Catalogue 2026 | Zodiac Catalogue 2026
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) |
|---|---|---|
| 1/2" | 15mm | ~21.2–21.5 mm |
| 3/4" | 20mm | ~26.6–26.9 mm |
| 1" | 25 mm | ~33.4–33.7 mm |
| 1.5" | 40 mm | ~48.1–48.4 mm |
| 2" | 50 mm | ~60.2–60.8 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. These are based on PVC Pressure Pipe AS/NZ 1477 Dimensions1.
- 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.
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).
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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SP7820502