How to source a complete drain air test kit
Fix the intended drain test and a shared parts specification before ordering. Source the main component from a checked maker, bring the accessories together in China, and approve an assembled kit for fit, leakage, measurement and packing. Coordinate the suppliers and kit inspection through Cambridge China Bridge.
Start with a kit specification and named suppliers
Choose the main component, such as the drain bungs, through buying from 1688. Check whether the seller makes that component, then source the manometer, hand pump, hoses and connectors around its approved interfaces. Give each supplier the relevant drawing and keep a master BOM identifying quantities, materials, supplier part references and permitted substitutions.
Name who receives the components, resolves shortages, assembles the sample and releases finished kits. Agree acceptance of the complete kit before committing to production. Use the supplier payment guide for payment staging; accessory suppliers should receive their own specifications and acceptance terms.
Fix the test the kit must support
Approved Document H is building regulation guidance for England. For underground pipes up to 300mm diameter, its air-test guidance specifies 110mm water gauge held for approximately 5 minutes before testing, then an initial 100mm pressure with a maximum manometer head loss of 25mm over 7 minutes. Specify readable measurement at these pressures and sufficient range for conditioning.
Approved Document H refers buyers to BS EN 1610 for further information and larger sizes. Its reference does not reproduce that standard's pressure table. Those figures could not be verified on the permitted official sources, so they are omitted here. For a BS EN 1610 order, obtain the selected method, test pressure, conditioning pressure, allowable drop and duration from the buyer's authorised standard before choosing the instrument range.
Specify each component and its interfaces
Use the product specification guide for the purchasing document. Enter actual dimensions and tolerances from approved drawings instead of accepting catalogue descriptions such as universal fitting. Select bung sizes from the pipe internal diameters and materials your customers use; nominal pipe size alone does not establish sealing fit.
Keep drain test pressure separate from any inflatable bung's inflation pressure. Ask for the bung's permitted back pressure, installation instructions and restraint arrangement. Specify a hand pump that allows controlled pressurisation and release, and approve how it is isolated during the test.
| Component | Specification to fix |
|---|---|
| Bungs or plugs | Pipe internal diameter coverage; mechanical or inflatable design; sealing rubber compound and hardness; body and fastener materials; test port dimensions; pressure ratings. |
| U-tube water manometer | Usable pressure range; scale in mm water gauge; smallest division and reading convention; zero adjustment; tube and case materials; upright support; connection dimensions. |
| Hand pump | Controllable output range; isolation and release valves; body and seal materials; outlet dimensions; connection to the drain circuit. |
| Hoses | Internal and external diameters; length; material and flexibility; pressure rating; end fittings and retention method. |
| Connectors | Thread designation, diameter and pitch; parallel or tapered thread; hose barb diameter; coupling profile; seal material; connector body material. |
Check what calibrated actually means
Treat calibrated as a claim to investigate. Request a certificate identifying the supplied instrument or batch, calibration date, method, reference equipment, measured errors and uncertainty at the intended working pressures. Check the laboratory's stated accreditation scope directly if accreditation is claimed. A generic certificate for another model does not establish your instrument's performance.
For the water manometer, check scale accuracy, zero setting, upright mounting and the instructions for reading the difference between water levels. Compare assembled samples against a traceable reference at the agreed working pressures. If a dial or digital gauge is included, agree its resolution and acceptable error separately. Record whether the evidence is factory verification or independent calibration; do not promise a universal recalibration interval.
Approve an assembled kit before bulk packing
Bring production-intent samples from every supplier to the same assembly location. Compare connector drawings, physically connect the parts, and test bungs in representative pipe sections across the agreed fit range. Check that hoses stay attached, seals seat correctly, valves isolate the pump and the manometer remains readable. Photograph the approved connection layout.
Leak-check the assembled equipment against a sealed reference fixture before using it to assess pipework. Record pressure behaviour, reference readings and any leaks at fittings or bungs. Agree acceptance limits and sampling in the order. Retain an approved complete sample and repeat the affected checks whenever a supplier changes a hose, seal, valve or connector.
Pack and barcode the complete kit
Use consolidation to receive the separate components and reconcile them against the kit BOM before packing. Agree protective compartments for the manometer, secured fittings and a packing checklist. Include assembly, filling, reading, pressure release and bung installation instructions. Label the kit with its stock code, contents, supported test method, measurement range and batch reference.
Assign the assembled kit a single stock code and approve the barcode artwork against the buyer's warehouse or retailer requirements. Follow the barcode validation guide and scan the finished pack. Keep component batch records linked to the kit batch. Approve the retail pack and outer carton separately, and distinguish retail kit identifiers from carton identifiers.
Frequently asked questions
Can I buy drain test kit parts from different factories?
Yes. Give suppliers shared interface drawings, bring their samples together and approve a complete functioning kit before bulk packing.
What pressure range should a drain test manometer have?
Choose the range from the specified test and conditioning pressures. For the cited Approved Document H test, it must cover 110mm water gauge and clearly show the allowed pressure drop.
Does a calibrated label prove a manometer is accurate?
Request the certificate, instrument identity, measured errors, uncertainty and reference details. Check performance at the pressures you will use.
Can the complete drain test kit have a single barcode?
Yes. Assign a kit stock code, approve the barcode with the receiving warehouse or retailer, scan the finished pack and retain component batch traceability.