Engineering Services

Conceptual design and the fundamentals of CNG station

Every fueling project starts with a research on basic calculations and conceptual design of the equipment and installation which is also a necessary step of the project. Some primary the measures include:

examining the feasibility of constructing stations and the general necessities

  • measuring compressor
  • measuring and executing storage tanks
  • calculating the number of dispensers
  • calculations related to the slow and fast fueling
  • maintaining practical standards
  • mother and daughter stations
  • designing engineering especial procedures for fueling issues
  • designing the process
  • preparing design criteria for under-pressure equipment
  • estimating the size and the type of the tubes and the joints
  • control logic design


Engineering of CNG compressor block

Designing and preparing the technology of compressor block manufacturing is the critically important technology of CNG industry and is considered as the heart of CNG stations:

  • Preparing the general and standard necessities
  • selecting and supplying the parts
  • assembly and test
  • maintenance and repair

CNG dispenser design

Designing and planning the technology of the CNG dispensers manufacturing and production as well as domestication of this technology have been fulfilled by TGP. This included the following steps:

  • maintaining standard and general necessities
  • P & I design and optimization
  • supplying the parts from domestic and foreign market
  • designing high pressure tubing system
  • 3D modelling
  • preparing manufacturing sketches
  • planning manufacturing procedures
  • designing electrical systems and wiring
  • designing control logic
  • planning project control
  • test and inspection as well as acquisition of technical and qualification certificates

Designing CNG compressor package

Technical knowledge of designing CNG compressor package is practically identical to that of the whole CNG industry. The process of planning the technology and manufacturing compressor packages include the following steps:

maintaining general and standard necessities

  • maintaining general and standard necessities
  • designing and optimization of R & ID
  • determining the technical characteristics of the parts
  • designing and calculating piping systems and the joints
  • 3D modelling
  • preparing manufacturing sketches
  • planning the manufacturing procedures
  • designing electrical system and wiring
  • designing control logic
  • planning maintenance and repair procedures
  • testing and inspection as well as acquisition of technical certificate

Design and manufacture of the air-gas package

Drier package of natural gas for the CNG stations is one of the expensive items whose technology and supply is not ubiquitous in the world. TGP has domesticated this technology by following a certain process. This process includes:

Planning the general and necessary necessities

  • designing and optimizing P & I
  • designing process
  • determining the elements characteristics
  • piping design
  • manufacturing procedures
  • designing electrical system and wiring
  • designing control logic

Engineering details design for the elements and equipment

In all the executed design and manufacturing projects, the major part of designing the elements and parts including structures, under-pressure tanks, welding and piping, mechanical parts, machining and casting are carried out under the supervision of the experts. The process are:

  • manufacturing sketch
  • workshop sketch
  • detailed list of the elements (MTO)
  • material technology and the technical characteristics of the primary materials
  • production process
  • quality control
  • testing and NTD

Distribution boards design and CNG stations panel control

TGP electric power and control team, in design and element manufacturing projects has been occupied with the design of control boards, capacitive, and distribution boards, design of wiring and control circuits and power as well control logic. The measures include:

  • maintaining the general and standard necessities
  • determining the technical characteristics of the elements
  • designing electrical system and wiring
  • designing electrical circuits
  • designing control logics









Design of controlling system and fuel station SCADA (supervisory control and data acquisition)

Designing remote monitor and controlling the station equipment via modems and telecommunication lines are other parts of TGP activities and They also include:

making compatibility in the station equipment and equipment control software

  • hardware design
  • software design
  • system implementation and operationalization

Purchase engineering

Engineering service with the purpose of supplying the elements and specialty equipment for oil and gas as well as CNG industries include:

  • introducing the supplier and evaluating it

  • preparing datasheet and determining characteristics of technical elements
  • managing technical evaluation and sale business
  • purchasing and supplying the specialty goods

Production engineering

TGP have had several experiences in consulting and managing production lines after compiling technical knowledge of testing and technical approval of the equipment such as  compressor package, drier package, CNG  dispenser, under-pressure storage tanks, control boards , etc.

  • planning the manufacturing procedure
  • planning QCP quality procedures
  • planning the testing process
  • planning inspection of ITP quality procedures
  • production supervision
  • scheduling, controlling, and guaranteeing quality


Fourth agency, Contractor’s management

Engineering and planning management

  • project leadership and guidance
  • solving engineering problems
  • stipulating standard regulations
  • ordering and administering technology transfer
  • planning and project controllin g

Technical documents’ supervision


  • examining the designs and doing the primary calculations
  • inspecting datasheets and equipment technical features
  • controlling manufacturing, testing, and inspection procedures
  • quality control plans
  • risk and engineering cost controlling

Engineering offices evaluation

  • examining the quality and engineers and technicians’ skills
  • examining the employed software and hardware
  • evaluating the quality and the relationship between the level of experience and the project
  • examining the methods of applying the codes and standards
  • examining the guarantees for quality in engineering


Inspection of manufacturing workshop

  • supervising the supply, production and controlling of raw materials, packaging quality, storage, inspection, and transportation of the elements
  • element production workshops
  • sub-contractors workshops
  • main assembly and test workshop
  • the plants which are established abroad


Supervision of the CNG station building and its installation

  • supervising technical issues of the building and facilities
  • technically supervising the mechanical facilities
  • technically supervising the electrical and explosion proof facilities
  • supervising non-professional tests
  • testing and checking the compatibilities with certificate and standards

Supervision of CNG station operating and performance

  • supervising operators issues
  • supervising the repair and maintenance
  • technically inspecting the equipment
  • inspecting the healthiness of working environment and the safety of equipment and the site
  • customers’ issues


Supplying the equipment and CNG and gas specialty parts

TGP is active in the issues related to the integrated engineering and equipment supply of fueling stations, both trans-regionally and internationally. It, also, has started its specialty activities in neighbor countries and Africa, in addition to the domestic markets.

  • large and navy stations
  • small and medium stations
  • house slow fueling devices
  • mobile stations of fluid and CNG
  • CNG and fluid transportation trailers
  • CNG mother and daughter stations
  • LPG stations

Equipment and specialty items of CNG and fueling systems supplied via domestic and foreign producers are:

  • CNG compressor package
  • CNG drier
  • CNG storage tanks
  • CNG dispensers
  • priority panels
  • controlling and electrical systems
  • sensors and transmitters
  • manual and automatic valves and security valves
  • spare and consumable items and equipment
  • photometer, hose and nozzle, controller, and other spare items for dispensers
  • various kinds of electrical elements and explosion-proof electromotor

Modifying the car kits and tanks in order to workshop change of the car to bi-fuel cars, which can use CNG or LPG in addition to oil, is one of our company activities. Also, giving general engineering guidelines and training engineers to select, install and test various kits on different cars with the collaboration of Iranian and foreign companies is another part of TGP Company in regard with the bi-fuel cars.


After sale services in CNG station

Installation and operation

TGP, as a leading company in installation and operation of a wide variety of CNG stations equipment domestically or overseas, and due to its integrated management and corporation of its engineers, present the best work quality in this area. The activities include:

  • managing installation team
  • supplying bulk material
  • supplying tools and facilities of installation
  • planning the installation procedures
  • testing and inspecting equipment
  • operating the equipment
  • resolving the equipment flaws and installing them on the site

Maintenance and service

The most important and complex area of activities in CNG stations are maintenance and repair of the complicated and weary equipment in the stations. TGP, with having skilled personnel and supportive engineers as well as strong director is a leading and approved company in the maintenance sector of CNG stations. Services in this area is provided for a wide range of technologies including Greenfield, safe’, Intermac, LMF, Delta, Scholem, DWP, etc. The services include:

  • periodic maintenance and service of the equipment
  • A, B, C, and D service ranks
  • compressor fundamental repairs
  • supplying the spare parts and items
  • supplying the special tool
  • troubleshooting and resolving the mechanical and electrical flaws and software problems of the equipment
  • inspecting and supervising the performance of stations’ safety systems
  • restarting up the troubled stations


Operating CNG stations

TGP company, because of its technical advantages and its high maneuver power in technical services and maintenance and supplying the spare parts of the equipment, has started to operate some of the troubled station in various regions of the country. The company with its experienced director and appropriate organization attempts to keep these stations active and beneficial. The operations include:

  • educating operators and issuing certificates
  • managing human resources
  • managing equipment maintenance
  • managing CNG sale operations
  • supplying spare parts and consumable materials

Now, Tarh Gostar Pouyesh with operating more than 15 CNG fuel stations throughout the country is one the most well-known operator companies in this area.

Operation and maintenance of Lordegan mother and daughter stations

TGP in line with operating and maintaining CNG stations and after planning the mother and daughter technology in Nigeria and obtaining enough experience in this area, tried to operate and maintain Loredegan’s mother and daughter station in Chaharmahle Bakhtiyari Province. Now, operation measures in Lordegan and fueling measures in four daughter stations located in Mamoor, Manj, Armand and Sardasht Town are started.



Training is a key area in all the industries. TGP as an experienced engineering company in CNG technology has done a lot with regard to holding training courses in operation, engineering, engineering sources, production, supervision and inspection, and changing the cars in workshops. The aim of all these was to help the industry to progress in the country.

  • maintaining the level and the topics of training pamphlets
  • organizing and training logistics
  • coordinating the lecturers and maintaining courses
  • qualification of the trainees’ technical skills


Engineering explosion proof systems  in hazardous area

Electrical explosion-proof elements and Equipment have wide uses in oil and gas systems, especially in CNG industry. Considering the importance of selection, supply, installation and maintenance of such equipment in hazardous area, TGP has long been pre-occupied with testing and supervision technologies of such equipment. After binding contracts with the most reliable center of testing and approving such equipment in the world, called PTB from German, it is following the measures below to transfer the technology to Iran and service CNG stations:

  • giving engineering consultation in the manufacturing and supply of the parts
  • engineering supervision of the manufacture and installation of the equipment
  • periodic inspection after supply and maintenance
  • testing the equipment and explosion-proof parts
  • holding explanation and training classes and seminars
  • creating regional experiments for explosion-proof equipment
  • specialty maintaining and repairing explosion-proof equipment
  • supplying the explosion-proof goods and tools
  • maintaining related standards for the industries



In all the quality managerial system, measurement equipment calibration, or in other words, periodically inspecting the equipment is an important part of the job. Since CNG facilities are critical and especially safe, they have a smart system of controlling the stages and performance. This system of facilities has instruments such as pressure and temperature sensors and actuators such as safety valves, pressure switches, temperature sensors and gas and fire flame sensors. One the other hand, according to the announcement of Gas Service Company and the Company of Gas Distribution and Filtering, gas sale to the public must be exercised carefully. Therefore, it is necessary to check the installed flowmeters and measure their deviation every six months. Therefore, if they are deemed right, then they can continue working. In this way, Tarh Gostar Pouyesh has started to fabricate control devices for various kinds of fuel dispensers so that the devices may control the flowmeters.


TGP- S 7 Calculator design and construction for the gas price
TGP-S7 Calculator

Due to the importance of calculating the exact price of the sold gas for the fueling car in natural gas stations and the high technology of design and construction of these electrical boards, Tarh Gostar Pouyesh Company, with help of God, succeeded to design and construct the gas price calculator board so that CNG industry does not need to rely on other countries.

Technical characteristics of TGP- S7 Calculator

  • calculating the price for two nozzle simultaneously
  • having the capability of forming single or triple lines
  • communication supporting system of MDBUS and frequency
  • The capability of being connected to the 24 and 220 volts valves
  • displaying 4 digits for the price and 6 digits for the consumption amount


Address: Unit 8, Forth floor, No. 406, Esteghlal Building, Hengam Street, Esteghlal Intersection, Tehran – PC/1687836368

021-77188920-1 | 02177220267-9 | 02177189767

Fax: 021-77220278


Messaging system: 500051504