Boiler house

Level controls

Local regulations may restrict the use of this product to below the conditions quoted.

In the interests of development and improvement of the product, we reserve the right to change the specification without notice. © Copyright 2015

2.3.17

LP20

Capacitance Level Probe

TI-P402-39

AB Issue 9

5

6

2

1

3

4

Description

The Spirax Sarco LP20 is a capacitance probe designed for

modulating level control in conductive liquids, in conjunction with a

PA20 preamplifier, which is supplied separately. It can also be used

for adjustable on/off control.

The LP20 may be used with one or more controllers or transmitters

to provide level control, level alarms, and/or outputs to a building

management system.

The probe is normally installed in a steam boiler or metal tank where

it is earthed through the 1⁄2" BSP screwed connection, the boiler or

tank forming the earth return path.

It may be used in a non-conductive tank (e.g. plastic or concrete) if

an earth rod is provided.

The PA20 preamplifier (described in separate literature), is screwed

to the top of the probe and hand tightened, enabling easy removal

without the need to disturb the probe.

Approvals:

The LP20 is also available with a 1⁄2" NPT screwed connection,

approved to UL61010. Please note that this version will not be

marked and is not suitable for Europe.

Caution:

The probe is not suitable for outside installation without

additional environmental protection.

Available probe lengths (approximate) in mm

370, 470, 550, 600, 650, 750, 800, 900, 950, 1050, 1200, 1350

or 1500.

Note: Probe length includes the 25 mm 'dead' length at its tip.

The probe must not be cut to length.

PA20

Preamplifier

connector

Pressure / temperature limits

Nominal pressure rating

Maximum pressure

Maximum temperature

PN40

32 bar g

239°C

70°C

5°C

Maximum

Ambient temperature

Designed for a maximum cold hydraulic test pressure of 60 bar g

Minimum

Technical data

Sensing depth

Minimum conductivity

Materials

No. Description

1 Probe body

2 Cover assembly

3 Probe (sheathed)

4 Probe sheathing

5 'O' ring

6 Name-plate

Probe length minus 25 mm

5 μS/cm or 5 ppm

Material

Austenitic

stainless steel

Austenitic

stainless steel

Stainless steel

tube

BS EN 10088-3

(1.4306)

Type 316L

ASTM A269 Gr. 316L

PTFE

BS 6564 Grade UA Type 1

Nitrile rubber

Polycarbonate