Modular nitrogen and instrumentation air production unit


Modular nitrogen and instrumentation air production unit (hereinafter MNPU) serves to produce and store nitrogen as well as treated instrumentation air for process needs.

Components composition

MNPU components composition is defined considering unit's parameters and individual customer's requirements.

Standard package of MNPU includes the following process equipment:

  • compressor;
  • air receiver;
  • nitrogen generation unit;
  • compressed air dryer;
  • piping and shutoff valves;
  • a set of instrumentation devices;
  • shelter-block.

Operation description

Air compressor performs air intake from unit’s premise and compresses it to achieve required pressure. Air receiver is designed to follow compressor block to avoid compressed air fluctuation. Receiver volume is defined based on compressor’s capacity.

Compressed air is partially fed to air dryer, where air drying and treating occur to achieve parameters determined in data sheet.

The rest of the air is supplied to nitrogen diaphragm-type unit for nitrogen production of required concentration. Diaphragms for nitrogen unit are made in the USA or Japan (depending on unit’s type).

Electrical equipment for MNPU includes manual local power control panel for ventilation and lighting systems. MNPU is equipped with the full set of cable structures and cable products.

MNPU process equipment is completed with local control and metering devices and transducers for automatic control of all process parameters: flow, pressure, dew point temperature etc.

MNPU operates automatically and does not require constant presence of service personnel.

Technical specification

MNPU capacity by nitrogen

5-5000 nm3/h

MNPU capacity by instrumentation air

5-5000 nm3/h

Nitrogen concentration, vol. %

95 – 99,95*

Instrumentation air dew point temperature

minus 40°С or minus 70°С

Nitrogen and instrumentation air pressure at the outlet of MNPU

4,5…13 kgf/sm2

Shelter-block dimensions, LхWхH




* - required nitrogen concentration is defined in data sheet.

If required instrumentation air pressure exceeds 14 kgf/sm2, increasing booster compressors which follow air druer unit are to be designed.

If required nitrogen pressure exceeds 14 kgf/sm2, booster compressors are to be installed before nitrogen unit, because for high pressure of inlet air a special diaphragm series is applied which allows to reduce unit’s dimensions ensuring high capacity by nitrogen.

Order placement

MNPU order placement is performed based on data sheet indicating capacity, operating pressure and customer’s requirements to nitrogen and instrumentation air treatment.

An example of a record designation necessary for order placement of MNPU with capacity 10 nm3/h and climatic performance for moderate and cold climate: БПА-10-УХЛ1 ТУ 3641-015-45211680-2007 «Nitrogen production modular unit. Technical requirements».