Measure the distance

How to get your allowances spot on

All licensed plumbers need to understand our requirements when they take measurements for installing light or heavy duty water meters. The distance that can be allowed between the pipes depends on the size of the meter. Measurements need to be accurate, as they help us to safely read, maintain and exchange meters in the future.

Find out more about how to install a meter correctly
Download our Water meter installation guide (945KB).

20mm to 50mm light duty meters

50mm to 300mm heavy duty meters

20 mm to 50 mm light duty meters

You need to measure between the ends of the threads to work out the distance needed to allow for these light duty meters. The arrows on the image show where to start and finish measuring.

Once you've done this, you can use the measurements below to work out your distance. 

The arrows show where to start and finish measuring.

 

Meter size (DN) – drinking water Distance to allow – drinking water

20 mm

260 mm

25 mm

310 mm

32 mm

350 mm *

40 mm

350 mm *

50 mm light

340 mm *

The right-angle stop valve and elbow have male BSP threads.

* This doesn't include the distance for the backflow prevention device.

 

Meter size (DN) – recycled water Distance to allow – recycled water

20 mm

270 mm

25 mm

265 mm

The right-angle stop valve has a female BSP thread.

The elbow has a female BSP thread.

You need to allow a minimum of 300 mm clearance around light duty meters. This helps us to safely read, maintain and exchange them in the future.

When you have your distance right, you need to insert a bridging piece where the meter will go. We'll remove the bridging piece when we install the meter.

The bridging piece

You need to insert the bridging piece where the meter will go. We'll remove it when we install the meter.

A correctly installed meter

If everything is done correctly, we won't have any problems installing a meter later on.

50mm to 300mm heavy duty meters

To work out the distance required for heavy duty meters, measure between the flange ends. Flange ends have flat surfaces instead of threaded ones.

Heavy duty meters have extra parts. You need to allow distance for these, too.

Use these measurements to work out your distance.

Meter size Gate valve Dirt box Distance piece inlet Meter Distance piece outlet Meter assembly space

50 mm heavy duty

175 mm

208 mm

372 mm

311 mm

150 mm

1,216 mm

80 mm

203 mm 

252 mm 

396 mm 

413 mm 

240 mm 

1,504 mm 

100 mm

229 mm 

260 mm 

476 mm 

483 mm 

300 mm 

1,748 mm 

150 mm 

267 mm 

406 mm 

762 mm 

500 mm 

450 mm 

2,385 mm 

200 mm 

292 mm 

428 mm 

1,000 mm 

520 mm 

600 mm 

2,840 mm 

250 mm 

330 mm 

522 mm 

1,250 mm 

450 mm 

750 mm 

3,302 mm 

300 mm 

356 mm 

580 mm 

1,500 mm 

500 mm 

900 mm 

3,836 mm 

You must allow a minimum of 500 mm clearance around these meters. This is so we can exchange them in future.