Pressure Switches - General Information0 pages

Data sheet
Date
Page

INFO SWITCH
05/2011
1 of 4

GENERAL INFORMATION FOR PRESSURE AND TEMPERATURE
SWITCHES

INTRODUCTION
All pressure switches are of automatic reset and tested and manufactured under ISO9001 and comply with the following.
Connection threads
All switches have threads according to :
EN 837-1/7.3.1 – 7.3.2 – 7.3.3 and 7.3.4. Parallel pipe thread (symbol G) according ISO 228-1.
Tapered pipe thread (symbol NPT) according ANSI/ASME B1.20.1.
Weatherproof standard for switches
IP65 (IEC529).
Oxygen and acetylene version
Wetted parts materials comply with EN 29539 and EN 837-1/9.7.2/S1.
Free of oil and grease.
Certified material specification
All stainless steel and other exotic materials used in production for connections, flanges, bourdon tubes, diaphragms
(wetted parts of the pressure switches) etc. are traceable, all materials are according to DIN EN 10204 – 2.2 or 3.1 (b).
PED directive
All the pressure switches are manufactured according to PED directive in cat. III, with release of relative conformity
declaration. The PED directive is not applicable to the temperature switches since these instruments are not pressure
apparatus.
ATEX directive
Pressure switches may be manufactured in accordance with ATEX directive gr. II cat. 1/2GD with protection mode
EExdIICT6 or supplied with conformity declaration for use in Intrinsically Safe circuits EExiaIICT6.
Temperature switches are instead available with conformity declaration for use in Intrinsically Safe circuits EExiaIICT6
Quality control
PCI’s instruments are produced under the rigid codes of the instrumentation industry and QA standards ENISO9001:2008. Our company ISO procedures are continuously controlled and monitored by NQA.
TERMINALOGY
Pressure or temperature switch : is a blind instrument, sensitive to the changes of the measured process variable and
opens or closes an electric circuit at a pre-set value.
Deadband (or differential of the micro switch ) : is the difference between the pre-set value and the value at which the
micro switch resets.
Repeatability : It is the shift of the switching point against the set point value initially calibrated during successive
switching .It is indicated in percentage of the full scale.
To evaluate the quality of a switch, it is not important to verify the accuracy but its value of repeatability since the accuracy
of the set point depends only by the accuracy of the test instrument used to calibrate the set point
_______________________________________________________________________________________________
PCI (Process System Solutions) Ltd, Unit 7 Slaidburn Crescent, Southport, Merseyside, PR9 9YF, UK,
Tel: +44 (0) 1704 509090, Fax: +44 (0) 1704 509091,
email: sales@pci-instruments.com, Website: www.pci-instruments.com