Sewage and Effluent Water Meter, DN50–DN300

Overview

Why buyers choose it

Clearances for dirty water

The rotor runs with the clearance effluent needs, rather than the tight fit that makes a clean-water meter accurate and blockable.
No power, no earthing

A mechanical meter totalises a trade effluent discharge without the supply and earth an electromagnetic meter requires.

To DN300 and 600 m³/h

Sized for a works outfall rather than a branch connection.
Remote reading to order

A remote transmission device can be added, with pulse output at 100 or 1000 litres per pulse, so an outfall can be logged without a site visit.

In detail

Clean-water meters fail on effluent for a predictable reason: the running clearances that make them accurate are the clearances that rag and grit block. This meter is the Woltman arrangement opened out for dirty duty, DN50 to DN300, with permanent flow from 15 to 600 m³/h.

It is a mechanical meter, so it should be specified where the effluent carries solids in suspension rather than settleable debris, and where a screen upstream is part of the design. Used inside those limits it gives a totalised volume for a trade effluent discharge or a works outfall without the power supply and the earthing an electromagnetic meter needs.

The declaration is to the 1993 edition of ISO 4064 in accuracy class A. That is a coarser class than the current edition's class 2, which is honest for the duty — nobody meters sewage to drinking-water tolerances — but it means the figures should not be read across to a current-edition specification without checking.

Where it is used

Bulk supply
Industrial

Standards

ISO 4064

Technical specifications

Selected size: DN50

Values shown apply to the selected size. A dash means the figure is not stated.

Metrological

Nominal size	DN50
Accuracy class	Class A (ISO 4064:1993)
Maximum permissible error, Q1 to Q2	±5%
Maximum permissible error, Q2 to Q4	±2%
Indicating range	999,999
Resolution of indicating device	0.0002

Hydraulic

Q3 permanent flow	15 m³/h
Q1 minimum flow	1.2 m³/h
Maximum working pressure	16 bar
Q2 transitional flow	4.5 m³/h
Q4 overload flow	30 m³/h

Environmental

Temperature class	≤30 °C (hot-water version ≤90 °C)

Approvals

Standards	ISO 4064:1993

Dimensions and installation

Connection thread	Flange
Length	200 mm
Weight	12 kg
Height	253 mm
Flange outside diameter	165 mm
Bolt circle diameter	125 mm
Connecting bolts	4 × M16

Parts

Parts of a Woltmann meter

How a meter of this type is built, and what this model is made of.

Illustrative: how a meter of this type is built. This model's own materials and figures are in the table and its specifications.

Register cover

Caps the register and keeps water and debris off the dial.
Register

Totalises and displays the water passed.
Register seal

Seals the register housing against water ingress.
Chamber cover

Bolted cover giving access to the measuring element inside the body.
Helical-vane rotor

Spins with the flow along its helical vanes and drives the register through a gear train.
Body

Flanged cast body that houses the rotor and carries the flow.
Flange gaskets and bolts

Seal and secure the flanged joints to the pipeline.