Making flow visible and adjustable.

Not billing, and usually not control.

Commissioning sets design flow in each branch.

Later measurement diagnoses complaints.

They are instruments and fittings, not meters.

The purpose is verification.

By differential pressure across a known restriction.

Two test points sit either side of it.

An instrument reads the pressure difference.

The valve characteristic converts it to flow.

Setting and characteristic must match.

Manufacturer data is required to interpret it.

Because it survives the commissioning engineer.

A documented system is checkable years later.

An undocumented one is an unknown.

The usual response to a complaint is to open something.

That unbalances everything downstream.

Records are the actual deliverable.

A permanent place to take a reading.

No breaking into pipework is needed.

Any system likely to be modified benefits.

They repay cost at the first investigation.

Position them where branches divide.

Record their locations with the drawings.

Exactly as to any flow measurement.

A reading next to a bend describes nothing.

Upstream and downstream lengths are specified.

This is easy to overlook on small branches.

The number still looks entirely plausible.

Check the installation before the reading.

It is needed and frequently absent.

Test points end up above ceilings and behind casings.

An unreachable point cannot be used.

That makes future verification impossible.

Coordinate access at first fix.

Record where every point is.

It removes much of the iteration, not the verification.

PICVs set flow independently at each terminal.

Proportional balancing largely disappears.

Being able to measure remains valuable.

Faults still need diagnosing.

Keep measurement capability in the design.