Woltman Hot Water Meter

A Woltman bulk meter rated to 90 °C.

Nominal size: DN40
Q3 permanent flow: 15 m³/h
Accuracy class: Class B (ISO 4064:1993)
Maximum working pressure: 16 bar

Select nominal size (DN)

Specifications update with the selected size.

DN40 1½″ DN50 2″ DN80 3″ DN100 4″ DN150 6″ DN200 8″

Documents

Download datasheet

Overview

Why buyers choose it

Rated to 90 °C

Bearings and rotor are specified for continuous hot service, not for a cold meter's occasional excursion.
Low head loss at high flow

On a circulating system the meter is a permanent restriction, so the pressure it costs is a running cost.

Removable measuring element

The element exchanges without cutting the body out, which on a hot line means no drain-down.
Dry dial, magnetically driven

The register stays clear and readable where steam and condensation would fog a wet dial.

In detail

Most bulk meters are declared for cold water and quietly lose accuracy above 30 °C. This one is built for the hot line: DN40 to DN200, rated for water up to 90 °C, with the bearing and rotor materials chosen for continuous service at that temperature rather than occasional excursions.

The applications are the ones a cold meter fails at — a district heating return, boiler make-up on a works, a laundry or process line where hot water is bought by volume and has to be accounted for.

The measuring element is removable and the dry dial is magnetically driven, so the register stays legible and the element can be exchanged without taking the body out of the line. Head loss stays low at high flow, which matters on a circulating system where the meter is a permanent restriction.

Where it is used

Bulk supply
Industrial
Commercial

Standards

ISO 4064

Technical specifications

Selected size: DN40

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

Metrological

Nominal size	DN40
Accuracy class	Class B (ISO 4064:1993)
Register type	Dry dial, magnetically driven
Maximum permissible error, Q1 to Q2	±5%
Maximum permissible error, Q2 to Q4	±2%
Indicating range	999,999
Resolution of indicating device	0.0005

Hydraulic

Q3 permanent flow	15 m³/h
Q1 minimum flow	0.45 m³/h
Maximum working pressure	16 bar
Q2 transitional flow	3 m³/h
Q4 overload flow	30 m³/h

Environmental

Temperature class	≤50 °C (hot-water version ≤90 °C)

Approvals

Standards	ISO 4064:1993

Dimensions and installation

Connection thread	Flange
Length	280 mm
Flange outside diameter	150 mm
Bolt circle diameter	110 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 type Dry dial, magnetically driven
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.

Download centre

Everything you need to specify.

Documents for the Woltman Hot Water Meter.

Approvals and certificates

Woltman Hot Water Meter

Why buyers choose it

Rated to 90 °C

Low head loss at high flow

Removable measuring element