Flow Regulator or Restrictor?
Both reduce flow. Only one of them holds a number you can put in a specification.
What a restrictor does
A restrictor is a fixed narrowing in the water path. Push more pressure behind it and more water comes through; the rate it delivers is whatever the pressure of the moment produces. It is cheap, it has no moving parts, and in a building with stable pressure it is perfectly adequate.
The restrictor in this range is ABS and PP in two options: 6 L/min in black, and 9 L/min in the original colour. The colour coding exists so a maintenance team can tell them apart after installation, which is a small thing that saves a lot of dismantling.
What a regulator does
A regulator holds a predefined constant flow rate independent of the prevailing line pressure, compensating automatically for pressure variations between 1 and 8 bar. Inside, a flexible element deforms as pressure rises and closes the gap it flows through, so the rate stays where it was set.
That 1 to 8 bar range is the specification that matters. Any building where the pressure at 7am differs from the pressure at 2pm — which is most buildings with more than a few outlets — will deliver different flow rates through a restrictor at different times of day. A regulator will not.
Which one to put in a tender
If the document says the outlet shall not exceed a stated rate, you need a regulator, because a restrictor cannot guarantee it at the top of the pressure range. If the goal is simply to bring consumption down and the pressure is known and steady, a restrictor does the job for less money.
The same logic applies inside an aerator. The constant-flow and honeycomb cores in the aerator range are regulators by another name — one is rated 8-9 L/min from 150 to 550 kPa, another holds 7L at 3 bar, and the honeycomb bodies are specified to hold constant flow at 45 PSI.
Where the shower regulators fit
The two shower regulators here go between the shower outlet and the hose: one on an F1/2 standard rated 9L, the other F1/2" by M1/2". Nothing else in the shower changes — not the head, not the hose, not the bracket.
For a retrofit programme this matters more than the hardware does. An intervention that touches one joint can be done by a maintenance operative in minutes. An intervention that replaces the head becomes a procurement exercise about which head.
Confirm the thread before you order
Both shower regulators are specified by thread, and the restrictor options are specified by rate and colour. Those are the two facts to send with an enquiry.
If you are ordering hidden or vandal-resistant aerators at the same time, order the service keys with them — M22x1 or regular female, M24x1 or regular male with side flats, and M28x1.
Need this confirmed for your own order?
Send us the thread size, the flow rate and the quantity. We reply with the specification and pricing.