GF iFIT: the push-fit system – d16 to d32 without a press machine

What iFIT is meant for – and where the limit lies

Drinking water, heating and air-conditioning installation on the floor level: connection lines, manifolds, radiator connections, bathrooms in series. GF names PN 10 at 10 bar, 70 °C and 50 years of continuous operation. The strength of the system is the workmanship: it needs no special technical knowledge and no press machine, which is why the same crew can carry out several trades – that is the reason iFIT is specified in prefabricated housing and in the refurbishment of large residential estates. The limit is part of it: d16 to d32, 70 °C, 10 bar. For risers of larger size, industrial applications, compressed air and gas iFIT is no substitute for a press or metal system.

How the push-fit joint works

The pipe is cut to length and chamfered and calibrated with the iFIT tool. Then the iFIT adapter is pushed onto the pipe end as far as it will go – the adapter holds the grip ring, which secures the pipe against pull-out, and two O-rings, which seal. The inspection window of the adapter must be completely filled by the pipe: that is the visible insertion depth. Finally the module is pushed onto the adapter until it clicks audibly. There is no pressing. When the pipe is pulled, adapter and module may slide apart by up to 5 mm – according to GF this is the dynamic holding mechanism and not a defect. The modular adapter technology makes one module usable for two sizes (d16/d20 and d25/d32), which according to GF halves the range.

Because nothing is pressed, there is no “leaks when unpressed” profile either: the check is the visible insertion depth and the leak test. Both belong to the installation, not to the optional extras.

Pipe, sizes and availability

iFIT joins polybutene pipe (in coils, also in conduit) and multilayer composite pipe PE-RT II/Al/PE-RT II (straight lengths and coils, also pre-insulated). The table shows the four sizes; we stock iFIT.

The standard names dimensions. What is listed here, we carry – from stock or to order; how quickly something is available we clarify on request. From stock: modules (coupling, reducer, elbow, tee, threaded transitions, manifold, valve connection), pipe and tools – shop category fittings/plastic.

Which medium with which limits

GF names drinking water, heating and air conditioning with 10 bar and 70 °C. Cooling water is an open technical question; compressed air and gas are excluded.

Detachable, module reusable – what that means

The iFIT joint can be detached – according to GF, however, not without damage: the adapter housing is unscrewed with two water pump pliers, the adapter is then destroyed and is not used again. The module, on the other hand, is reusable: the pipe end is shortened by 6 mm, chamfered and calibrated again and pushed in again with a new adapter. That is a difference from every press joint, which can only be cut out, and an advantage for corrections during the fit-out and for conversions. We list the detachability as a manufacturer statement by GF. In the joining methods comparison push-fit therefore appears under the criterion detachability as “detachable (manufacturer statement)”.

What was learned from the early days of push-fit systems

That push-fit systems are less widespread in Germany than in other countries also has to do with their reputation from the early days. The early cases of damage at push-fit joints had typical causes: a pipe end that is not chamfered cuts into the O-ring when inserted; a pipe that is not calibrated is out of round and does not seal over the whole circumference; an insufficient insertion depth lets the pipe creep under pressure surges; pipes with too large a tolerance sit loosely; fittings without locking do not withstand tensile forces. Each of these causes has a design answer today – with iFIT like this: chamfering and calibrating are mandatory steps with the system tool, two O-rings seal, the grip ring in the adapter holds the pipe against pull-out, the inspection window of the adapter shows the insertion depth, the sealing rings are fitted at the factory, and the system is approved for pipe and module together (DVGW). What remains is the care in preparing the pipe end: whoever chamfers, calibrates, slides the adapter on as far as it will go and lets the module click into place gets a joint that is tested by the same rules as a press joint. Whoever skips a step has the same source of error as twenty years ago.

The second reason does not lie in the technology: the installer bears the warranty for a joint he will not see again later – and the press system gives him with “leaks when unpressed” a proof that the push-fit system does not have in this form; here the check is the visible insertion depth and the leak test. Add to that the press tools already in the business. Both explain the reserve better than any guess about motives – and neither speaks against the push-fit system where it belongs: on the floor level, in series, in refurbishment.

Transitions

Transition modules with male and female thread (brass, lead-free gunmetal), transition elbow modules, valve connection modules and manifold modules lead from iFIT to valves, threaded fittings and – via thread to EN 10226-1 – to all metal and press systems. Flow rule and material pairing as in every mixed installation.

Push-fit or press?

Pressing (Mepla, FlowFit, Raxofix) reaches up to d75, needs machine and jaws and is not detachable; push-fit (iFIT) ends at d32, needs only chamfering and calibrating tool and is detachable. Where speed, low demands on the installer and few tools count – prefabricated housing, bathrooms in series, refurbishment in occupied buildings – iFIT is the right choice; where sizes above d32, compressed air or industrial media are required, a press system. More under multilayer and push-fit systems and From our practice.

Installation in brief

• Cut the pipe square, chamfer and calibrate with the iFIT tool – without chamfering the O-rings suffer.
• Slide the adapter on as far as it will go (inspection window completely filled), push the module on until it clicks audibly; pull briefly – up to 5 mm of play is permitted according to GF.
• Leak test, record.
• Pipe routing with fixings after manufacturer statement; do not expose multilayer pipe permanently to daylight.

Availability at Zickwolff

The standard names dimensions. What is listed here, we carry – from stock or to order; how quickly something is available we clarify on request. We stock iFIT: modules, polybutene and multilayer pipe, tools.

Further reading

Tools of this section: system finder (which system suits medium, pipe and size) · joining methods compared (press, push-fit, grooved, welding, thread, flange, soldering) · cost comparison calculator (assembly time and downtime per method) · press systems overview.

Related multilayer and push-fit systems

Matching items from our range: malleable iron fittings for threaded transitions, plastic piping systems by GF, valves.