Description
From pipe to a female port
Bring 25mm MDPE pipe to a compatible female-threaded fitting with this straight adapter. Its grey compression end receives the pipe, and the ½-inch BSP male thread projects from the black body into the mating female socket.
One adapter is supplied. The installation shows the connection between a pipe and a separate valve; the pipe, valve and support clip are not included.
Check the pipe, then the port
25mm identifies the pipe outside diameter. Check the exterior of the MDPE pipe rather than its internal bore or the width of the grey nut.
½-inch BSP identifies the external male thread. It needs a matching female-threaded component. Its outside thread diameter is about 21mm; BSP is a nominal sizing system, so ½-inch is not a direct 12.7mm measurement across the thread.
Match the thread form and sealing requirements too. If either connection differs, compare the MDPE straight joiners and threaded adapters for a suitable pairing.
Make room for a supported joint
Keep access to the compression nut and avoid loading the plastic threaded end.
Prepare the MDPE end
Isolate and depressurise the supply. Prepare a clean, square end on suitable 25mm OD MDPE pipe and check whether a separate pipe liner is needed.
Align the threaded end
Follow the mating components’ sealing and tightening guidance. Start the male thread squarely in the female port and avoid forcing or overtightening the plastic spigot.
Support and inspect
Support adjoining pipework and fittings without strain on the adapter. Assess the PN10 designation against the complete system and service conditions, then restore the supply gradually and inspect both connections.
Choose the connection type
Does this screw onto a male-threaded tap?
No. This adapter has an external male thread and needs a compatible ½-inch BSP female port. For a male-threaded component, choose an appropriate female adapter.
Can I use this instead of a 25mm equal coupling?
They do different jobs. This adapter connects one plain MDPE pipe end to a threaded component. An equal compression coupling joins two matching plain pipe ends.
Product information & technical details
| SKU | MDPESTR25-12BSPM001 |
|---|---|
| Product type | |
| BSP thread size | 1/2" |
| Thread gender | Male |
| MDPE size | 25mm |
| Colour | Black, Grey |
|---|---|
| Material | Plastic |
| Connection | 25mm outside-diameter MDPE compression socket × ½-inch BSP male thread. |
| Pressure designation | PN10. Confirm suitability for the complete assembly and service conditions. |
| Pack contents | One adapter. Pipe, valve, support clip and any separate pipe liners or thread-sealing materials are not included. |
What is BSP?
What is BSP thread size?
BSP (British Standard Pipe) is a nominal pipe-thread size, not a direct measurement of a fitting’s bore or outside diameter. For example, a ½-inch BSP male thread measures about 21mm across its outer thread crests.
These figures are approximate outside diameters of male BSP threads, to help identify the nominal size. They are not inch-to-millimetre unit conversions:
- 3/8" BSP → 16.66 mm
- 1/2" BSP → 20.95 mm
- 3/4" BSP → 26.44 mm
- 1" BSP → 33.25 mm
- 1.25" BSP → 41.91 mm
- 1.5" BSP → 47.80 mm
- 2" BSP → 59.61 mm
- 3" BSP → 87.88 mm
- 4" BSP → 113.03 mm
All our BSP threads are parallel (BSPP, to ISO 228), not tapered.
Measure across the outside of a male thread, then check its pitch and whether it is parallel or tapered. Diameter alone does not confirm compatibility. Check the product’s stated thread specification before connecting.
All delivery times are estimates and not guaranteed. Orders placed before 1 pm, Monday to Friday (excluding bank holidays), will be dispatched the same day, while orders placed after 1 pm will be dispatched by the end of the next working day.
If an invalid postcode or address is provided, the order will be cancelled without further notice, as we are unable to modify addresses or print labels for invalid postcodes.
Our standard delivery option is Royal Mail Tracked 48, which typically takes 3–5 business days. If you need your order more quickly, Expedited delivery via Royal Mail Tracked 24 is available, offering a 1–2 business day service.
Large or bulky items may be sent via courier at our discretion and are usually dispatched for next-day delivery. Please note that we only ship to mainland UK addresses; delivery to non-mainland locations, including the Highlands & Islands, may not be available for large or heavy items. If your address falls into one of these areas and you wish to purchase such items, please contact us with your postcode and order details before placing your order. If we cannot ship to you, you are welcome to arrange your own courier for collection.
All products, unless otherwise stated, come with a standard manufacturer warranty against faulty workmanship.
If your product fails within six months of delivery, please contact us with your order reference number, a description of the issue, and clear images illustrating the fault.
Should your item require a return for further investigation, it is your responsibility to arrange and cover postage back to us.
If we are unable to repair the fault, we may offer either a replacement or a full refund.
In cases where the item is inspected and found not to be faulty, or where damage is determined not to be due to manufacturing defects, you will not be entitled to a refund or replacement. We will then either return the item to you via standard post or dispose of it at your request.
You may return any order within 14 days of delivery. As soon as you receive your items, please inspect them carefully, taking reasonable care to keep both the product and its packaging clean and undamaged. If you discover an error or defect after 14 days, we reserve the right to decline your return. If your product fails or breaks after this 14-day time window then your order may be eligible for a warranty claim, please see our warranty information for more details.
To initiate a return, please contact us via our contact form to obtain a return authorisation and the correct returns address (different from the address on your invoice). This can also be done through your 'recent orders' page on your account if you are registered with Shop. Returns sent without prior authorisation will be discarded.
Returned items must be in the same condition in which you received them: unworn or unused, with tags attached and in their original packaging. You must include either a copy of your invoice or a slip with your order reference number inside the parcel. Please be sure not to obscure your return reference number on the label.
If you refuse delivery or reject the parcel without prior notice, we will inspect the returned package and issue a refund upon receipt. Although there is no restocking fee, we will deduct the cost of the return postage label (£3.35) from your refund.
If the returned item or its packaging shows signs of use, damage, or staining, we may deduct up to 50% of the order value, or refuse the return entirely, depending on its condition. Examples include damaged tags, stained, modified or damaged packaging, or missing components.
For faulty, incorrect, or damaged items, please contact us before sending anything back so we can attempt to resolve the issue directly. If we agree that a return is necessary due to our error, we will provide you with a pre-paid return label.
Products that have been modified or damaged through customer action are not eligible for return. This includes, but is not limited to, items that have been cut, trimmed or otherwise altered (such as a tarpaulin or pond liner resized to your specifications), or any product showing damage beyond normal inspection handling.
All delivery times are estimates and not guaranteed. Orders placed before 1 pm, Monday to Friday (excluding bank holidays), will be dispatched the same day, while orders placed after 1 pm will be dispatched by the end of the next working day.
If an invalid postcode or address is provided, the order will be cancelled without further notice, as we are unable to modify addresses or print labels for invalid postcodes.
Our standard delivery option is Royal Mail Tracked 48, which typically takes 3–5 business days. If you need your order more quickly, Expedited delivery via Royal Mail Tracked 24 is available, offering a 1–2 business day service.
Large or bulky items may be sent via courier at our discretion and are usually dispatched for next-day delivery. Please note that we only ship to mainland UK addresses; delivery to non-mainland locations, including the Highlands & Islands, may not be available for large or heavy items. If your address falls into one of these areas and you wish to purchase such items, please contact us with your postcode and order details before placing your order. If we cannot ship to you, you are welcome to arrange your own courier for collection.
All products, unless otherwise stated, come with a standard manufacturer warranty against faulty workmanship.
If your product fails within six months of delivery, please contact us with your order reference number, a description of the issue, and clear images illustrating the fault.
Should your item require a return for further investigation, it is your responsibility to arrange and cover postage back to us.
If we are unable to repair the fault, we may offer either a replacement or a full refund.
In cases where the item is inspected and found not to be faulty, or where damage is determined not to be due to manufacturing defects, you will not be entitled to a refund or replacement. We will then either return the item to you via standard post or dispose of it at your request.
You may return any order within 14 days of delivery. As soon as you receive your items, please inspect them carefully, taking reasonable care to keep both the product and its packaging clean and undamaged. If you discover an error or defect after 14 days, we reserve the right to decline your return. If your product fails or breaks after this 14-day time window then your order may be eligible for a warranty claim, please see our warranty information for more details.
To initiate a return, please contact us via our contact form to obtain a return authorisation and the correct returns address (different from the address on your invoice). This can also be done through your 'recent orders' page on your account if you are registered with Shop. Returns sent without prior authorisation will be discarded.
Returned items must be in the same condition in which you received them: unworn or unused, with tags attached and in their original packaging. You must include either a copy of your invoice or a slip with your order reference number inside the parcel. Please be sure not to obscure your return reference number on the label.
If you refuse delivery or reject the parcel without prior notice, we will inspect the returned package and issue a refund upon receipt. Although there is no restocking fee, we will deduct the cost of the return postage label (£3.35) from your refund.
If the returned item or its packaging shows signs of use, damage, or staining, we may deduct up to 50% of the order value, or refuse the return entirely, depending on its condition. Examples include damaged tags, stained, modified or damaged packaging, or missing components.
For faulty, incorrect, or damaged items, please contact us before sending anything back so we can attempt to resolve the issue directly. If we agree that a return is necessary due to our error, we will provide you with a pre-paid return label.
Products that have been modified or damaged through customer action are not eligible for return. This includes, but is not limited to, items that have been cut, trimmed or otherwise altered (such as a tarpaulin or pond liner resized to your specifications), or any product showing damage beyond normal inspection handling.