1. Central Medical Gas System
Arif Raza

2. Introduction
Gases and Vacuum are used in hospitals for therapeutic purposes
The gases used in hospitals are
Medical Gases
Oxygen
Nitrous Oxide
Compressed air
Vacuum

3. Introduction
Centralized gas and vacuum supply service is a modern system of piped supply of medical gases from a central storage area called manifold room to all delivery points in hospital
It provides a very efficient, economical and highly dependable life support service
Makes better patient care in all the areas of hospital

4. Functions Supply of right medical gases at right pressure
Supply of compressed air at right pressure
Supply of clinical vacuum at right pressure
Proper planned maintenance of all equipments, including distribution network
Optimum level of cleanliness and pollution free environment
Prevention of hazards such as fire, explosion or contamination of gases supplied

5. Components
Source of supply: Central supply room with control equipments and panels
Distribution system: piping
Point of use delivery connections: Suitable station outlet valves and pendants
Monitoring and control equipment and alarms

6. Manifold Room Consists of a cylinder manifold and a control panel
Manifold can be of 2 banks of 2 cylinders each or 2 banks of 20 cylinders each
Control panel: primary and secondary pressure regulators; warning lamp
Pressure gauges

7. Manifold Room Vacuum Unit Vacuum pump with an electric motor
Cylindrical reservoir tank: stabilizes the pressure of the pipeline system at all outlet points
Motor has switch for automatic start and stop
Vacuum pumps are duplexed

8. Manifold Room Compressed air unit
Compressor with electric motor, after cooler, air receiver and air dryer
Instantly provides compressed air
Compressor are duplexed

9. Manifold Room Primary supply
Secondary supply when primary supply is exhausted
Primary and secondary provides normal operating supply
When operating supply fails, a reserve supply takes over

10. Manifold Room
In case of breakdown of control panel of oxygen and nitrous oxide, an emergency kit ensures supply of gas through the pipes
Emergency kit comprises a regulator and high pressure tubing to a bulk cylinder and the gas is fed directly to the pipeline through a service outlet
In case the vacuum and air supply system fails, a standby motor-cum-pump is used to provide uninterrupted supply

11. Manifold Room
Half of the total daily consumption of oxygen and nitrous oxide is kept in the manifold room as reserve
Oxygen and nitrous oxide should be stored seperately from flammable gases and liquids
Storage location should be free of combustible materials
If exceeding 2,000 cubic feet storage should be outside the building
Must have generator backup, adequate ventilation, lighting and telephone communication

12. Advantages of Centralized Medical Gas System
For the patients
No distressing sight of oxygen cylinders at the bedside
Elimination of irritating noise from movement of cylinders
Protection of contamination due to movement of cylinders
Uninterrupted and clean supply at desired location

13. Advantages of Centralized Medical Gas System
For Hospital Staff
Instant availability of gas on taps
Clean, safe and reliable delivery of gases
Continuous flow of gases when and where required
Minimal accident hazards due to mishandling of cylinders

14. Advantages of Centralized Medical Gas System
For Hospital Administrator
Easy purchase of gases in bulk quantities at favourable terms
Economy on purchase of cylinders
Fewer breakages
Rationalization in ordering, storing and transporting a wide variety and size of gas cylinders
Minimum damage to building due to handling of cylinders

15. Oxygen Increased demand of oxygen
May be supplied from a bulk tank or from cylinders
Can be stored as gas or liquid
Oxygen containers may be stationary or movable

16. Oxygen and Nitrous Oxide
Bulk oxygen system: assemblage of equipment such as oxygen containers, pressure regulators, safety devices, vaporizer, manifolds and interconnecting piping with a storage capacity of more than 20,000 cu ft of oxygen including reserves
The system terminates at the point where oxygen first enters the supply line at service pressure

17. Vacuum Used for patient draining, aspiration and suction
Also used in hospital laboratory
Distributed through network of pipes
Central vacuum supply system with control equipments, an alarm and piping
The piping terminates with outlet valves at user points

18. Vacuum
Central vacuum consists of two (or more) vacuum pumps that operate either simultaneously or alternately
Each pump should be capable of maintaining 75% of calculated demand during peak time
The pumps should alternate automatically
Pumps should be equipped with a motor starting device and overload protection
Failure of one vacuum should not affect other

19. Compressed Air
Compressed air is used for both medical and non-medical puposes
Medical use – Laboratory work, inhalation therapy equipment and powering of surgical tools
Non-medical use – maintain tools and equipments and in engineering department

20. Compressed Air Should be free of dust and moisture
Done by means of oil filters, dust filters, moisture seperator and the dryer at equipment level
Separate dryer for air compressor system
If compressed air not used properly, it can damage equipment and contaminate chemicals, food and drugs

21. Pipes
Should be seamless type, non-ferrous, non-arsenic, of high quality copper tubing
Should be protected against physical damage and corrosion
Exposed oxygen pipelines should not be installed in areas like kitchen, laundry and rooms where combustible materials are stored
Colour coded as per the gas content

22. Pipes
Before pipes are erected, all pipes, tubes and fittings should be cleaned thoroughly and washed with tetrachloride
Pipes should be blown clear using oil-free air or nitrogen
When whole system is in place, it should be subjected to a test pressure of 150 psi or 1 ½ times the working pressure for 24 hours to check, if it can withstand the pressure as well as leakages
This test, called pressure lock is done section by section

23. Terminal units Gas outlets / vacuum inlet units
Connected to source equipment through the distribution system
Located at actual usage point
Outlets should be gas specific and non-interchangeable
Fitted with locking system and non-return valves

24. Alarm system Audio-visual Monitoring of pressure
Meant to warn maintenance dept

25. Location and space Ground floor in rear part Near maintenance area
Seperate enclosure for full cylinders, empty cylinders, compressed air, vacuum supply
No fire hazard
Compresor unit in sound proof area
Liquid oxygen area shall be cordoned off

26. Staffing No specific norms
Total 6 technicians (including supervisors and 25% leave relief)
Under chief engineer

27. Quality Indicators
Number of complaints of malfunctioning, from the users
Correctness of pressure level in the oxygen, nitrous oxide and compressed air pipeline
Correctness of negative pressure in the vacuum line
Bacteriological culture of the gases and the air delivered
Leakage at the outlet points
Functioning of audio-visual alarm system

28. Thank You