Pharmaceutical engineering: Handling of Gases

1. PHARMACEUTICAL
ENGINEERING

2. UNIT- 4: HANDLING OF STEAM AND GAS
 Cylinder, steam traps, valves and pipes and pipe handling system. (2 hours)

4. PROPERTIES OF GASES
 # Diffusion nature of gases
 Compressibility
 Pressure and temperature dependent
 Safety

5. PRINCIPLES OF MATERIAL HANDLING
 Gases Risks
 Handling Storage of gas cylinders
 Colour marking of gas cylinders
 Gas equipment
 Regulations and rules

6.  Nitrogen
 Oxygen
 Acetylene
 Helium
 Propane
 Temperatures: from -269 C up to +3.500 C
 Pressure: from 0 to 300 bar
 Purity: up to 99,99999%
 Medical Oxygen • Nitrous oxide • NO-mixtures
 Carbon dioxide & -monoxide
 Hydrogen
 Argon
 Inert Gases (Kr, Ne, Xe)
 Methane
 Inhalations
 Aerosols/Propellents

7. IMPURITIES IN GASES
 Traces of hydrocarbons
 trace amounts of water
 Other Gases
 Particulate matters

8. USE OF VARIOUS GASES IN PHARMACEUTICAL INDUSTRIES
 Helium is the gas of choice for use with the thermal conductivity detector (TCD), and allows greater sensitivity
as compared to nitrogen.
 The electron capture detectors (ECD), on the other hand, are more efficient when nitrogen or argon–methane
mixtures are used as carrier gas, while no noticeable difference in sensitivity is evident between nitrogen and
helium when using the flame ionization detector (FID).
 Thermionic detectors (TD), such as the nitrogen–phosphorus detector (NPD) utilize nitrogen or helium as the
carrier gas
 Similarly, the photoionization detector (PID) uses oxygen-free nitrogen or helium, while nitrogen is used as
carrier gas with the flame photometric detector (FPD).

9. GASES CONTROL EQUIPMENT AND DEVICES
 Flow Control
 Cylinders
 Temperature controls
 Valves
 Traps
 Piping system
 Pumps

14. COMPRESSORS

15. PUMPS
 Machines delivering gases are
commonly called compressors or
blowers. Compressors discharge at
relatively high pressures, and blowers,
at relatively low pressures. The lower
density and viscosity of gases lead to
the use of higher operating speeds
and, to minimize leakage, smaller
clearance between moving parts.

16. CYLINDERS
 Features
 Different Size and shape
 Color
 Thickness of wall
 Storage and handling techniques

17. CYLINDERS: IDENTIFICATION AND PROPERTIES
 Read the label to see what gas you are dealing with and double check tha the cylinder/gas is right for th
eintended use
 No compressed gas cylinder should be accepted for use that does not legibly identify its contents by name
 If the labeling on a cylinder becomes unclear or an attached tag is defaced to the point the contents
cannot be identified, the cylinder should be marked "contents unknown" and returned directly to the
manufacturer
 Never rely on the color of the cylinder for identification. Color coding is not reliable because cylinder
colors may vary with the supplier. Additionally, labels on caps have little value because caps are
interchangeable
 If there is a mismatch between the color of a cylinder and the label. Do not use, contact the supplier
immediately
 Know the properties of the gas (read Material Safety Data Sheets available from your Supervisor)
 The cylinder’s contents should be identified at all times as well as the cylinder status (full, empty or in
service)

18. CYLINDERS: WORK PRACTICE
 Read the label to see what gas you are dealing with and double check tha the cylinder/gas is right for th eintended use
 No compressed gas cylinder should be accepted for use that does not legibly identify its contents by name
 If the labeling on a cylinder becomes unclear or an attached tag is defaced to the point the contents cannot be identified, the cylinder should be marked
"contents unknown" and returned directly to the manufacturer
 Never rely on the color of the cylinder for identification. Color coding is not reliable because cylinder colors may vary with the supplier. Additionally, labels on
caps have little value because caps are interchangeable
 If there is a Securely restrain cylinders to prevent them falling over
 Close the cylinder valve and replace dust caps when cylinder not in use
 Before connecting a gas cylinder to equipment or pipework make sure regulator and pipework are suitable for the gas and pressure being used
 Never drop a gas cylinder
 Never tamper with cylinders or subject them to abnormal mechanical shocks which could damage the valve or safety device
 Never re-paint, change markings or identification or interfere with threads
 Never disguise damage to a cylinder or valve. Label as faulty and contact the supplier
 Never attempt to repair a cylinder
 Never scrap a cylinder
 Never subject cylinders to abnormally high or low temperatures
 Never mix gases in a cylinder
 Never try to refill a cylinder unless properly trained to do so
 Never transport by rolling them on the ground or use them as rollers or supports
 Never pick them up by magnetic lifting
 Never subject to abnormal mechanical shocks whuch could damage the valve or safety device
 Know the properties of the gas (read Material Safety Data Sheets available from your Supervisor)
 The cylinder’s contents should be identified at all times as well as the cylinder status (full, empty or in service)

19. CYLINDERS: WORK PRACTICE
 1. Daily Inspection

20. GAS CYLINDER REGULATORS
A regulator is a device that receives gas at a high pressure and reduces it to
a much lower working pressure
 Precision instruments and MUST be handled with care to avoid damage to
their sensitive springs, diaphragms, valve seals etc.
 Equipment should display the relevant European/British Standard number
and the pressures up to which it can operate
 Leave the pressure adjustment knob/screw fully out when the regulator is not
in use (this ensures a minimum of tension on the springs and diaphragms)
 Cylinders should be placed with the valve accessible at all times. The main
cylinder valve should be closed as soon as it is no longer necessary that it be
open, it should never be left open when the equipment is unattended or not
operating
 This is necessary not only for safety when the cylinder is under pressure, but
also to prevent the corrosion and contamination resulting from diffusion of air
and moisture into the cylinder after it has been emptied.

21. HOSES
 Correct hose bore size, pressure rating, length and color coding are essential for safety BS EN 559
 Blue – oxygen, Red - acetylene and other fuel gases(except LPG)
 Black – inert and non combustible gases
 Orange – Liquified Petroleum Gas
 Never use hoses that are longer than necessary
 Never use equipment while hoses are wrapped around the cylinders or trolley
 Length of hose should be suitable for the task
 Keep hoses in good condition
 Examine the hose for cracks, deterioration, damage and test the hose for leaks before use
 Do not repair hoses unless you have the skill and means to test hem in accordance with BS En 1256
 Purge hose thoroughly before lighting torch
 Do not put wrapping tape around hosing as this contains combustible hydrocarbons
 Do not use copper piping with acetylene hoses as it is potentially explosive
 Protect hosing from heat, oil, grease or mechanical damage

22. PIPES
 The many pharmaceutical processes that involve the transfer of a gases confer great importance on the study
of flow in pipes.

23. PIPES
 Distribution lines and their outlets should be clearly labeled as to the type of gas contained
 Piping systems should be inspected for leaks on a regular basis
 Special attention should be given to fittings as well as possible cracks that may have
developed

24. STEM TRAPS
 Steam trap is a type of automatic valve that filters out condensate (i.e. condensed steam) and non-
condensable gases such as air without letting steam escape.
 If condensate is not drained immediately or trapped from the system, it reduces operating efficiency by
slowing the heat transfer process and can cause physical damage

25. STEM TRAPS
 The job of the steam trap is to get condensate, air and Co2 out of the steam heated unit as fast as they
accumulate. In addition, for overall efficiency and economy, the trap must also have following design and
operating consideration
 Minimum steam loss
 Long life and dependable service
 Corrosion resistance
 Air venting
 CO2 venting at steam temperature

26. STEM TRAPS
 Types Mechanical traps operate by using the difference in density
between steam and condensate. A float within the trap detects the
variance in weight between a gas and a liquid.
 Thermostatic traps detect the variation in temperature between steam
and condensate at the same pressure. The sensing device operates
the valve in response to changes in the condensate temperature and
pressure. Thermodynamic Traps use volumetric and pressure
differences that occur when water changes state into gas. These
changes act upon the valve directly

27. HANDLING GAS CYLINDERS
 Wear PPE: gloves, protective footwear, eye protection
 Correct way to move cylinders is to: keep upright, secure and with valves uppermost
 Use mechanical aids such as a trolley where reasonably practicable( do a risk assessment)
 Use suitable cradles, slings, clamps or other effective means when lifting with a hoist or crane
 For short distances on even ground the practice of ‘milk-churning’ (manually moving cylinders) can be
used only by trained personnel and never for longer distances, in uneven ground, wet or icy conditions,
poor lighting, or at speed a trolley should be used
 All personnel involved should have completed manual handling training
 Never roll cylinders along the ground
 Never transport cylinder with valve and pressure regulator attached or with the valve open
 Never attempt to catch a falling cylinder just get out of the way
 Never lift a cylinder by its cap, valve or guard/shroud

28. TRANSPORTING CYLINDERS
 If possible carry in open vehicles or trailers
 If they must be carried in closed vans/cars ensure good ventilation at all times
 If the load compartment is not separated from the driver do not carry toxic gas cylinders (those with a
toxic gas label and having yellow as a colour on the cylinder)
 Secure cylinders properly so they cannot move or fall in transit or do not project beyond the edges of the
vehicle, normally in the upright position unless instructions for transport state otherwise
 Ensure gas cylinders are clearly labelled to show contents and associated hazards
 Fit suitable protective valve caps and covers to cylinders

29. TRANSPORTING CYLINDERS
 Disconnect hoses and regulators from cylinders
 Carry propane cylinders upright and do not carry flammable gas cylinders in the same compartment as
toxic gas cylinders
 Do not smoke while carrying cylinders inside vans/cars
 Unload the cylinders as soon as possible and move to a well ventilated storage area
 If you suspect it is leaking, park the vehicle, investigate the fault and contact the supplier
 If you are involved in an accident advise, any emergency services involved what gas cylinders are being
carried

30. SAFE STORAGE
 It is best to store gas cylinders in the open and on concrete in a fenced compound
with some weather protection
 In storage areas oxygen cylinders must be stored at least 3 metres
away/separated by a fire wall from fuel gases such as acetylene, propane,
methane etc.
 Full cylinders should be stored separately from empties and empty oxygen
cylinders should be segregated from empty fuel gas cylinders
 Other products should not be stored in the gas storage areas especially not oil or
corrosive liquids, sources of ignition or flammable materials
 Ease of access into and around storage area, such as provision of aisle >0.6m to
prevent domino effect

31. SAFE STORAGE
 LPG cylinders have special requirements including storage 3m away from other
gases
 Pyrophoric and toxic gases should be stored seperately in locked, suitable
ventilated storage areas with restricted access
 Protect gas cylinders from external heat sources which may adversely affect their
mechanical integrity
 Cylinders should be secured and properly restrained, secure with straps or
chains connected to a wall bracket or other fixed surface, or by use of a cylinder
stand
 Cylinders should be clearly labelled to show contents and associated hazards

32. WARNING SIGNS

33. REFERENCE
1. Pharmaceutical Engineering –principles and practices by CVS Subrahamanyam, J T Setty, S Suresh and V K
Devi. Vallabh Prakashan Delhi.
2. Pharmaceutical Engineering by K Sambamurthy – New age international publisher.
3. Theory and Practice of industrial Pharmacy by Lacman and Lieberman.
4. Unit Operation by Anthony J Hiki
5. Pharmaceutical Process scale-up: by Michel Levin- Marcel Dekker.
6. Pharmaceutical production facilities; design and application by Cole G- 2nd edition Taylor Francis, 1998.
7. Pharmaceutical Process Engineering - Anthony J Hickey, Marcel Dekker 2001.