| PN |
nominal pressure |
| DN |
nominal inside diameter |
| D |
inner diameter of piping |
| d |
diameter of orifice plate,
nozzle or tube bore |
| Direction of flow |
direction of fluid (medium)
flow in the piping |
| Pressure differential |
difference of pressure in front
of and behind primary element |
| Chamber tapings |
taping of pressure differential
is usually made by ring (annular) slot on the whole
perimeter of piping |
| Individual tapings |
pressure differential taping
made by sole bore in front of and behind the orifice plate |
| Flange tapings |
axes of taping bores are
drilled 25.4 mm from front and back part of orifice plate |
| Straight lengths |
cylindrical piping of constant
section without any obstructions or branches |
| ÈSN |
Czech technical standard |
| ISO |
international standard |
| DIN |
German standard (Deutsche
normen) |
| ANSI |
American standard (American
National Standards Institute) |
| ASME |
American standard (The American
Society of Mechanical Engineers) |
| GOST |
Russian standard (Госстандарт
России) |
| ÈMI |
Czech Metrologyl Institute |
| SMU |
Slovak Metrologyl Insitute |
| TCM |
symbol of pattern approval
certificate given by ÈMI |
| TSQ |
symbol of pattern approval
certificate given by SMÚ |
| AMS |
Authorised Metrology centre |
| Authorisation Certificate |
authorising company for
verification of stated meters |
| Primary element |
differential pressure source, e.g.
orifice plate, nozzle, event. Venturi tube |
| Pattern approved meter |
meter approved by ÈMI, ensuring
ability to fulfil functions for designed functions and
fulfil requirements stated by regulation or requirements of
technical standards |
| Meter tube |
specially manufactured section
(of piping) to which orifice plate is built-in, complying
all requirements of standards |
| ISO5167 |
standard – measurement of fluid
flow through differential pressure indicator in the fully
filled piping of circular section |
| 11 grade steel |
construction steel |
| 15 grade steel |
heat-resisting (boiler) steel |
| 17 grade steel |
stainless steel |
| oval shape |
roundness deviation |
| inlet part of meter tube |
section (length) of piping in
front of orifice plate, counter flow |
| outlet part of meter tube |
section (length) of piping
behind orifice plate, downstream flow |
