Good practices for industrial valves maintenance – 1/8

In industrial valves, maintenance is an essential aspect for the performance of a site. You want to know the gestures and good practices of a successful maintenance? Manufacturer since 1921, Guichon has created a series of 8 sheets to better understand the maintenance of industrial valves.
The first one is about how to identify a product.

The steps

1 Visual observation of the valve

  • Identification of the operating system
  • Identification of the type of connection
  • Reading the engraving on flanges to identify the connection dimensions and the pressure class
2 Reading the marking plates

  • ATEX nameplate: identification of the type of site the valve can be installed on in respect of the level of dangerousity of the area and the flowing media (gas/vapors or dust)
  • Marking plate
  • Name of the manufacturer / Certification / n° of certifying body
  • Tag: valve reference in the equipment
  • Serial : manufacturer serial number
  • Body/Trim: material information
  • Size/Rating : dimension/pressure class
  • Shell test : test pressure of the enclosure
  • Ps/Ts & ΔP : operating and differential pressure
  • Date of the test performed by the manufacturer
  • Fluid/media Nature & Category (2014/68/UE)
  • arrow-right-bottom
    These 2 observations allow the identification of:
    – Fluid nature and type going through the valve
    – Construction materials (detection of incompatibilities)
    – Connection type for adequacy with the installation flanges
    + Face to Face directly taken with a tape measure

  • Actuator plate
  • Visual analysis: identify if there is a manual emergency device
  • Reading the pneumatic actuator nameplate:
  • guichon-plate

    Manufacturer name GUICHON VALVES
    ACTUATOR System identification
    SERIAL Serial N°
    FLUID Actuator feeding fluid
    VOLUME Actuator cavity volume (unit: liter)
    P min/max Operating conditions
    T min/max Mini/maxi pressure in bar – Temp in °C (or °F)
    MASS Actuator weight in Kg
    MAX FORCE Maximum force (KN unit)

    Examples of electric actuator plates

5 Documentation

  • Serial N° of the valve: allows to obtain other information from the manufacturer, particularly the overall drawing containing:
  • Dimensional data
  • Materials data
  • Pneumatic diagram
  • Flow direction
  • Installation, operation and maintenance instructions
  • The IOM supplied with the valve contains general instructions for installation, operation and maintenance.


Practical case

From the photos below, can you characterize this valve?

1 Visual observation Motorized valve
With flange
Flange: 3/4″ – Class 300
2 ATEX plate reading: II 3G II : aerial/surface installation
3 : in level 2 risk area
G : GAS fluid
3 Marking plate reading
EC Certification + certifying body n° CE 0035
TAG Reference on the installation site
SERIAL Manufacturer serial N°
Body Mat. Body material
Trim Mat. Internal parts material
Size Nominal diameter DN80
Rating Pressure Class 300 Lbs
Shell test Body test pressure
PS/Ts max Operating conditions
Ts min/max
Op. ΔP
05/19 = testing date by manufacturer PED category of the fluid Gas Group.1
4 Actuator plate readingguichon-plate

Actuator plate reading Single acting pneumatic cylinder with EMC (emergency manual control) Caution single acting = spring = precaution at disassembly
SERIAL Manufacturer serial number Allows to give references to obtain more details like overall drawing
FLUID Lubrificated Air Actuator feeding with lubricated air
VOLUME 5.9L Air volume for one stroke
P. min/max Operating conditions
T. min/max
MASS 93 KG Actuator weight
MAX FORCE 43kN Maximum load
5 Documentation General Assembly drawing

  • Dimensional information
  • Pneumatic diagram
  • Flow direction


Good to know

  • Class 300 flanges = design according to the ASME B16.34 American standard
  • CE Logo: valve designed and manufactured according to the Pressure Equipment Directive