Medical Gas & Steam Principles

Medical Gas & Steam Principles

Vacuum System In 1961, Centralsug AB installed the first vacuum waste system in the world at Sollefteå Hospital. The system is still in operation today with many original parts from the early 1960s.

Vacuum System • Is a network of piping systems connecting vacuum producing devices to suitable vacuum inlets where patient suction is needed • Medical Gas and Vacuum are governed by their classification • Level 1 • Level 2 • Level 3

Medical Piped Gas and Vacuum • Systems • Level 1 • Systems servicing occupancies where interruption of the piped medical gas and vacuum system would place patients in imminent danger of morbidity (create unhealthy condition) or mortality (death) • I.A.W. NFPA99--3.3.903.3.90

Medical Piped Gas and Vacuum Systems (Continued) • ICU • CCU • Surgery • OB/Delivery • Nursing • ER

Medical Piped Gas and Vacuum Systems (Continued) • Level 1 Vacuum System • System consisting of central vacuum, producing equipment with pressure and operating controls, shutoff valves, alarm warning systems, gauges, and a network of piping extending to and terminating with suitable station inlets at locations where patient suction could be required • I.NFPA99I.A.W. NFPA99--3.3.903.3.90

Medical Piped Gas and Vacuum Systems (Continued) • Level 2 • Systems serving occupancies where interruption of the piped medical gas and vacuum would place patients at manageable risk of morbidity or mortality • Wards • Clinics • I.A.W. NFPA99--3.3.91

The Level 3 Vacuum System (Continued) • Can be either: • A wet system designed to remove all liquids, air-gas, or solids through the service inlet • A dry system designed to trap liquid and solids before the service inlet and to accommodate air-gas only through the service inlet • I.A.W. NFPA99--3.3.933.3.93 • Dental Clinic • Surgery for scavenger system

Medical Piped Gas and Vacuum Systems • The Level 3 Vacuum System consists of; • Two or more vacuum devices/pumps hooked up in duplex/parallel located in a dedicated mechanical equipment area, adequately ventilated and environmental controls with any required utilities

Medical Piped Gas and Vacuum Systems (Continued) • The Level 3 Vacuum System • Must have Pumps that provide sufficient suction to service the peak calculated demand with the largest single vacuum pump out of service • Must have flexible motor/pump mounts and connecting pipes to control pump and motor vibration • Must have an automatic means to prevent backflow (i.e. check valve) from any on--cycle vacuum pumps through any off—cycle pumps

Medical Piped Gas and Vacuum Systems (Continued) • The Level 3 Vacuum System • Must have a shutoff valve or other isolation means to isolate each vacuum pump from the centrally piped system and other vacuum pumps for maintenance or repair without loss of vacuum in the system

Medical Piped Gas and Vacuum Systems (Continued) • The Level 3 Vacuum System • Must have a receiver/vacuum storage tank that meets the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section VIII, Unfired Pressure Vessel specification

Medical Piped Gas and Vacuum Systems (Continued) • Vacuum Storage Tank • If liquid goes into this tank, then isolation valves and fluid traps will be used in conjunction with drain valves to allow automatic liquid drainage • There will be a separate shutoff valves and connections between the vacuum pumps and the receiver • Will exhaust in a manner and location that will minimize the hazards of noise and contamination to the facility and its environment • Will be: • Located outside • At least 10 ft./3.050 mm from any door, window, air intake, or other opening in the building • At a level different from air intakes

Medical Piped Gas and Vacuum Systems (Continued) • Where prevailing winds, adjacent buildings, topography, or other influences that would not divert the exhaust into occupied areas or prevent dispersion of the exhaust • The end of the exhaust shall be turned down and screened or otherwise be protected against the entry of vermin, debris, or precipitation, by screening fabricated or composed of a non—corroding material

Medical--Surgical Vacuum Source Exhaust (Continued) • The exhaust line shall be free of dips or loops that might trap moisture. Where low spots are un--avoidable, a drip leg and drain valve shall be installed • Exhaust lines from multiple pumps can be joined if pipe back pressure is minimized in accordance with manufacturers recommendations • Each exhaust line will have an isolation valve installed to allow for servicing of individual pumps

Vacuum System Electrical Controls • Additional pump/s will automatically activate when the operating pump/s is incapable of adequately maintaining the required vacuum • Automatic or manual alternation of pumps shall allow division of operating time • If automatic alternation of pumps is not provided, the facility staff shall arrange a schedule for manual alternation

Vacuum System Electrical Controls (Continued) • Each pump motor shall be provided with electrical components including, but not limited to, the following: • Dedicated disconnect switch for each motor • Motor starting device • Overload protection • If transformers are required there will be a separate transformer for each motor • Power circuits arranged in such a manner that the shutting down of one pump does not interrupt the operation of another pump

Alarms, Indicators, and Gauges • Pump--motor alarm shall activate a local alarm when the backup or lag pump is running due to primary pump becoming inoperable • Vacuum and Pressure alarms and indicators will be adjacent to each other • Pressure gauges will indicate the normal operating pressure at mid-scale (ex. 50 PSI would indicate straight up on a 100PSI gauge) • Vacuum pressure gauge shall have an operating pressure range of 0 ––760 mmHg/0 ––29.9 in Hg, mid—range is 380 mmHg/12 in Hg

Pressure Gauges (Continued) • The area alarm panel contains the following: • Vacuum gauge • Gas pressure Gauge • Vacuum alarm • Gas pressure alarm

HYDRAULIC PRINCIPLES • Reason for Hydraulics • Almost 100% efficient • Provides instant application of power • Fluids will compress only a very small amount at extremely high pressure • Air in the system takes away from efficiency • Lightweight parts • Most components made of aluminum alloy • Smaller in size compared to other mechanical systems

HYDRAULIC PRINCIPLES • Lines easily routed • can be easily routed around most obstructions • Uses "Tee" fittings, elbows, cross fittings, etc • Self lubricating • Components operate in a bath of oil • Reduces friction and cools components • Safer • Hydraulically moved loads are safer than mechanically moved loads • Using hydraulic jacks compared to using mechanical jacks

HYDRAULIC PRINCIPLES • Properties of Fluids • Effects of temperature • When heated, fluid volume increases • When cooled, fluid volume decreases • Practically incompressible • Laminar flow • Smooth even flow (smooth movement) • Jerking/jarring movements seldom occur

HYDRAULIC PRINCIPLES • There is no pressure in a moving body of fluid • Resistance to fluid flow gives us pressure • Increase fluid flow, pressure will decrease • Decrease fluid flow, pressure will increase • Viscosity, thickness of fluid • Thick fluids have high viscosity • Thin fluids have low viscosity • Changes in temperature affect viscosity • Temperature increase, increase in volume • Temperature decrease, decrease in volume

HYDRAULIC PRINCIPLES • Hydraulic Laws • Pascal's law - states: • A force applied to a confined body of fluid, will result in pressure being applied equally and undiminished in all directions • The pressure is applied equally to all sides of the balloon, so the balloon is round • Bernoulli's law (Bur-new-lees) - states: • The pressure of a fluid decreases at points where the velocity increases • Restrictions cause the same amount of fluid to try to get through the smaller area • The fluid must move faster, result is increased velocity

HYDRAULIC PRINCIPLES • Relating Hydraulic Formula • Actuator - converts hydraulic pressure into useful mechanical force • Components of an actuator • Piston - what the fluid moves • Rod - what moves the subsystem • Cylinder - what the piston is inside of • Stroke - how far the piston and rod move • Extension stroke - actuator gets longer • Retraction stroke - actuator gets shorter

HYDRAULIC PRINCIPLES • Force formula - F = A x P • Force - the amount of push or pull on an object • The weight of something • Measured in lbs • Area - a measurement of surface • Piston surface • Measured in square inches • Pressure - the amount of force applied to a given area • a The result of resistance • b Measured in PSI (pounds-per-square inch)

HYDRAULIC PRINCIPLES • Problem Indications • Bubbling/hissing sound • Usually indicates low oil level • If oil level is good, the sound indicates that the system has air trapped in the lines, and requires bleeding: • There is usually a screw at the top of the system used to bleed the air from the system • Press lift lever down/activate the pump • Loosen screw to allow air out of the line

HYDRAULIC PRINCIPLES • Tighten screw before releasing the lever/deactivating the pump • Procedure may require repeating to ensure all air is removed from the line • Slow movement - look for some sort of obstruction, such as: • Dirty filter • Faulty solenoid • Faulty check valve • Maladjusted speed control

HYDRAULIC PRINCIPLES • Applications: • Tables • OR • OB • ER • Chairs • Dental clinic • Ear, nose and throat/ENT clinic • Equipment stands/columns • OR • ENT clinics

Physical Principles • Principles of Pneumatics is the branch of Physics that studies the properties of gases at rest or in motion • Atmospheric Pressure’s most common unit of measurement is millimeters of mercury (mmHg) • At sea level, atmospheric pressure is normally 760 mmHg (14.763 PSI) • In Kabul, Afghanistan atmospheric pressure is normally 579.1mmHg (11.2 PSI) atmospheric

Physical Principles (Continued) • The Ideal Gas Law explains the relationship of the absolute pressure, temperature and volume of any gas • This relationship is expressed by the equation P x V/T = K • P = Pressure • V = Volume • T = Temperature • K = Constant; different for each gas

Physical Principles (Continued) • If one variable changes; at least one other variable MUST also change to maintain the constant “K” (Example if Pressures doubles while temperature remains constant, then volume must decrease by 50% to maintain the constant “K”)

Gas Physics • States of matter: in our atmosphere there are four states of matter: solids, liquids, gases, and plasma • The state of matter of a substance largely depends on the kinetic activity (motion) that the molecules of that substance poses • The degree of motion is most dependent on the temperature of these molecules

Gas Physics (Continued) • Increase molecular velocity causes molecules to exert more force when they hit something because of their inertia, such as they collide with each other • Inertia (force) = mass x velocity • With increased force the molecules tend to move further apart causing an expansion

Gas Physics (Continued) • The movement and temperature increase of the molecules has the ability to change the molecules from solids to liquids, and liquids to gas

Gas Physics – Melting Point • Melting point is defined as the temperature at which transition occurs from a solid to a liquid state • At the melting point of a solid the kinetic activity is high enough for the molecules to break free from their own mass attraction sufficiently to escape and travel at random within the space of their containing vessel • The substance is now considered to be in the liquid state

Gas Physics – Boiling Point • Boiling point is defined as that point at which a transition occurs between a liquid and gaseous state at atmospheric pressure • As the temperature of the substance increases, the molecules of the liquid gain more and more kinetic activity and then travel around more freely and exert more force • At atmospheric pressure and at a temperature at which the molecules can break free from the attraction of the liquid, and begin to convert to a gas, is considered to be its boiling point

Sublimation • Sublimation: under certain conditions molecules can completely by-pass the liquid state • As the heat content increases and the molecules vibrate more vigorously, they may break loose below the melting point and become free gas molecules • Solid Carbon Dioxide (dry ice) is the most common example of this phenomenon • Every substance known to exist has its own melting and boiling point

Gas Pressure Measurement • Pressure: is defined as force per unit area. • The force of gas molecules hitting things because of their kinetic activity causes gas pressure • There are various types of apparatus used to measure gas pressure (examples are liquid barometers and gauges) • Barometers: basically form some type of equilibration of forces between the molecular gas pressure force and a mechanical or weight force

Mercury Barometer • The mercury barometer: uses the weight of a column of mercury to equilibrate with the kinetic activity (force) of the molecules hitting the surface of a mercury reservoir • A column is completely filled with mercury and erected with its opened end below the surface in the mercury reservoir • The mercury in the column attempts to return to the reservoir as a result of gravity, but the reservoir is subjected to the force of gas molecules hitting its surface

Mercury Barometers (Continued) • The force of the gas molecules pushes the mercury up the column from the reservoir • When the force of gravity on the weight of mercury in the column equals the gas pressure force, equilibrium exists and the gas pressure can be measured • This pressure is measured by the height of the mercury column (mmHg)

Aneroid Barometers • Aneroid Barometer: equilibrates/balances gas pressure force with mechanical force or the expansion force of an evacuated metal container • An increase in the atmospheric gas pressure on the surface of the metal container tends to compress it

Aneroid Barometers (Continued) • The change in the container’s dimensions is recorded by means of the gearing mechanism which changes an indicators location on a recording dial • Likewise a reduction of gas force surrounding the container allows the metal container to expand toward its normal shape

Bourdon Gauge • Bourdon Gauge is another mechanism that measures pressure • It consists of a coil tube and a gear mechanism on which an indicator is attached

Bourdon Gauge (Continued) • As the gas pressure within the Bourdon tube increases, its force is exerted on the top of the inside of the tube to a larger degree because of the larger surface area • This increasing pressure tends to straighten the tube, causing the indicator to rotate to a new location on a dial as a result of gearing mechanism

Units of Measurement • Atmospheric pressure: is a unit of pressure equal to the pressure of the air at sea level or approximately 14.763 pounds per square inch • The following illustrates units of measurements that are equal in terms of force measured at one atmosphere:

Units of Measurement (Continued) • Atmosphere is = 1ATM (atmosphere) • 14.763 pounds per square inch (PSI) • 29.21 inches of mercury (inHg) • 33.93 feet of water (ftH2O) • 1034 centimeters of water (cmH2O) • 760 millimeters of mercury (mmHg) • 101.3 kilopascals (kPa)

Medical Gas & Steam Principles