Penlon Sigma Delta Service manual

Sigma Delta Vaporizer Service Manual

Quality and Assurance in Anaesthesia

Servicing and Repairs

In order to ensure the full operational life of the Sigma Delta vaporizer, we recommend that a periodic service check should be performed by a Penlon trained engineer. This check comprises a vaporizer LEAK TEST and CALIBRATION CHECK. Note: (a) The calibration check must be performed using a suitable agent analyser, e.g. a Riken refractometer or infrared analyser. (b) The service check is part of the recommended pre-use check for your Anaesthesia System.

Should the calibration checks show the unit to be outside the specified performance requirement, then an overhaul service must be performed.

This may be done on site by: (a) A trained user. (b) An authorised Penlon agent. (c) A Penlon service engineer.

A calibration and service record section is provided in the user instruction manual to maintain a record of the vaporizer's performance.

For any enquiry regarding the service or repair of this vaporizer, contact the nearest accredited Penlon agent* or contact the Service Department at Penlon Limited.

Service and Repair Department Penlon Ltd Abingdon OX14 3PH UK Tel: +44 (0) 1235 547063 Fax: +44 (0) 1235 547062 E-mail: service@penlon.co.uk

Always give as much of the following information as possible:

1. Type of equipment

2. Product name

3. Serial number

4. Approximate date of purchase

5. Apparent fault

IMPORTANT

(i)

This manual has been produced to provide authorised personnel with information on the function, routine performance, maintenance checks and repairs, applicable to the Penlon Sigma Delta vaporizer. Information contained in the manual is correct at the date of publication. The policy of Penlon Limited is one of continued improvement to its products. Because of this policy Penlon Limited reserves the right to make any changes, which may affect instructions in this manual, without giving prior notice. Personnel must make themselves familiar with the contents of this manual before using the vaporizer.

Terminology

This manual complies with ISO 4135, Anaesthetic Apparatus Terminology. The following additional definitions should be noted:

Vol.% - shortened form of volumetric per-

centage.

The commonly used method of expressing vapour concentrations so that they can be compared with concentrations of true gases. 100 Vol.% is equivalent to 100% partial pressure in a mixture.

FOREWORD

(ii)

CONTENTS

User Responsibility 1

1. Warnings and Cautions 2

2. Purpose 4

3. Description 7

4. Specification 11

5 Service Procedures 12

5.1 Service Policy 12

5.2 Workplace and Equipment 14

5.3 Pre-Service Checks 18

5.3.1 Leak Test, Bypass Resistance Check (before servicing) 18

5.3.2 Fault Finding (before servicing) 19

5.4 Service Overhaul 21

5.4.1 General Information 21

5.4.2 Health and Safety 21

5.4.3 Service Overhaul Procedure 22

5.4.4 Leak Test, Bypass Resistance, and Calibration Check (after servicing) 64

6 Parts List 68

(iii) (iv)

This vaporizer has been built to conform with the specification and operating procedures stated in this manual and/or accompanying labels and notices when checked. assembled, operated, maintained and serviced in accordance with these instructions provided. To ensure the safety of this vaporizer it must be checked and serviced to at least the minimum standards laid out in this manual. A defective or suspected defective, product must not, under any circumstances be used.

The user must accept responsibility for any malfunction which results from non-compliance with the servicing requirements detailed in section 8.1.

Worn, broken, distorted, contaminated or missing components must be replaced immediately. Should such a repair become necessary it is recommended that a request for service advice is made to the nearest Penlon service centre,

This vaporizer and any of its constituent parts must be repaired only in accordance with written instructions issued by Penlon Limited, and must not be altered or modified in any way without the written approval of Penlon Limited. The user of this equipment shall have the responsibility for any malfunction which results from improper use, maintenance, repair, damage or alteration by anyone other than Penlon Limited or its appointed agents.

This vaporizer must only be supplied to, and used by, suitably qualified medical practitioners. Caution: USA and Canadian Federal Law restricts the sale and use of this device by or on the order of a physician.

Statements in this manual preceded by the following words are of special significance.

WARNING - means there is a possibility of personal injury to yourself or others.

CAUTION - means there is a possibility of

damage to the instrument or other property. NOTE - indicates points of particular interest

for more efficient and convenient operation.

The reader must take particular notice of the warnings, cautions,. and notes printed throughout the manual.

USER RESPONSIBILITY

WARNINGS

1. The Sigma Delta vaporizer is to be sold to, and used on the order of, a medically qualified practitioner only.

2. Anaesthetic agents are poisonous, and inhaling their vapours, even in low (sub-anaesthetic) concentrations may present a health hazard. Care must be taken to avoid spillage of anaesthetic drugs when filling or draining the vaporizer.

3. The procedures described herein which involve dismantling the vaporizer must only be performed after the instrument has been drained and dried out.

4. Calibration procedures must only be performed with the vaporizer outlet connected to an anaesthetic gas scavenging system designed in accordance with national standards or regulations.

5. No oil or grease should be permitted in the vaporizer service area. This applies equally to silicone based lubricants, flammable oil, and grease.

6. The Sigma Delta vaporizer is designed for use only with one anaesthetic agent - that which is named on the filler block. Misdosage will occur if the vaporizer is filled with the wrong drug. Keyed filler devices are provided on certain models to meet national and international standards.

7. The Sigma Delta vaporizer must not be modified or disassembled by any unauthorised person. It should be regularly serviced by a Penlon authorised service agent, trained technician or engineer and by no other person (see section 6).

8. The pharmacopoeia name of the drug is used on the label according to BP, USP or Ph EUR. The user is responsible for confirming that any trade name of a drug is equivalent to the registered name.

9. Violent movement or tipping of a filled vaporizer may cause liquid agent to leak into the control mechanism and subsequently deliver uncontrolled doses of vapour. The vaporizer must be empty, and the control must be in the zero position during transport.

The vaporizer must be purged at maximum output with 5 L/min flow of oxygen for 2 minutes, and the output checked with an analyser prior to use.

10. The vaporizer control must be in the zero position during the filling or draining process. Delivered concentrations are inaccurate while the standard filler port is open or the key filler shoe loose. The vaporizer must be upright during filling, to prevent overfilling.

11. Vaporizers may malfunction if exposed to excessively high temperatures, e.g. by storage above a radiator. This may permanently damage the vaporizer. Maximum storage temperature:

50oC (122oF) Minimum storage temperature:

-20oC (-5oF).

12. Vaporizer outputs are sensitive to barometric pressure and a correction factor may be necessary when assessing the output using an analyser, for example at high altitude. Barometric pressure effect are not usually of clinical importance. (See user manual).

1. WARNINGS AND CAUTIONS

13. Anaesthetic drugs must be treated as a pharmaceutical product. Liquid should never be drained from a vaporizer into an open container and then reused. Contamination is likely. Always dispose of such drained liquid as a hazardous chemical.

CAUTIONS

1. The instructions given in this manual assume that the service engineer has received adequate training in the practice of servicing anaesthetic apparatus and is familiar with the use of flowmeters, pressure gauges and other laboratory equipment. Details of such procedures are therefore not

included.

2. Each Sigma Delta vaporizer is a tested and calibrated unit. It is most important that components are not transferred from one unit to another. In particular, the service engineer must accept responsibility for ensuring that agent specific items such as labelling, keyed fillers, and control needles are treated as critical devices and that full records of vaporizer servicing are kept.

Following any service procedure, a label to indicate to clinical staff that the vaporizer has been serviced must be attached to each unit.

WARNINGS AND CAUTIONS

2. PURPOSE

The Sigma Delta vaporizer is designed for incorporation in the fresh gas supply system of continuous flow anaesthetic machines, directly connected between the flowmeter unit and the common gas outlet of the machine.

The vaporizer is unsuitable for use within a breathing system 'in circuit' because of the relatively high internal resistance.

Its purpose is the provision of accurate concentrations of anaesthetic drugs in the fresh gas supply, in accordance with the setting of the control dial, when the fresh gas supply flow is between 0.2 and 15 litres/min. Factors affecting output accuracy are listed in the user instruction manual (Section 7, Performance Characteristics), which shows the extent of modifications to the control calibration.

Cagemount

Selectatec

Drager

North American Drager

Delta Vaporizer

Connector Block Types

Figure 1 Gas Flow Path

Closing

mechanism

(On/off control)

Vapour

concentration

control needle

Temperature

compensator chamber

Spiral

passage

Vapour

chamber

Mixing

chamber

Gas

Flow

Out

Bypass

Flow

Saturated vapour

Gas

Flow

3.1 General Description

The Delta User Manual provides additional information on the operation of the vaporizer. The service engineer should have a copy for reference, in addition to this service manual.

Introduction

The Sigma Delta vaporizer enables the anaesthetist to add a predetermined amount of vapour of a volatile drug to the fresh gas stream supplied to the patient’s breathing

system. All anaesthetic agents of a volatile nature have relatively high vapour pressures at normal room temperature so that this saturated vapour must be diluted considerably to produce the concentrations required clinically.

Gas Flow Path

Figures 1 and 2 show that the vaporizer contains two paths for gas flow. One is always open, through the bypass system. The second, which is open only when the control knob is moved from zero, is routed via the closing mechanism vapour chamber,

and, vapour control orifice, and joins up with the bypass flow in a mixing chamber, and then on to the vaporizer outlet.

Vapour Chamber

The vapour chamber contains the liquid anaesthetic drug, and is filled through the filler unit to a level shown on the level indicator. The chamber contains a spiral wick assembly.

Gas which enters the chamber has to pass through the narrow passages between the wicks, becoming saturated with vapour before emerging through the vapour control orifice. The proportion of the total flow which passes through the vapour chamber is determined by the relative resistances of the bypass orifice (which does not vary with control knob setting, but does vary with temperature) and the vapour control orifice (which varies only with control knob setting). Compensation for total flow variation is achieved by the design of the orifice elements which are precision parts.

Temperature Compensation

Compensation for temperature variation (and therefore changes in vapour pressure, viscosity etc.) is achieved by the movement of a bypass control plate (in the form of a bimetallic strip) against the bypass orifice, thus changing the area of the orifice. This device is mounted within the vapour chamber so that it is exposed to both gas and liquid temperatures within the vaporizer.

Back-pressure Compensation

Compensation for fluctuating back-pressure on the vaporizer, as produced by the use of IPPV in the breathing system, is provided by: A) the inclusion of a long gas flow path prior to the closing mechanism system, and B) a spiral passage after the closing mechanism, which prevents reverse flow of vapour from the chamber into the bypass gas flow.

3. DESCRIPTION

Figure 2 Gas Flow Block Diagram

3.2 Concentration Control

and Cut-off Mechanism

3.2.1 Control Knob Assembly

The laser engraved dial is etched to match the performance characteristics of the components of the individual vaporizer using its allotted agent. A self-adhesive label, colour coded for the agent to be used with the vaporizer, is fixed to the knob.

3.2.2 Dial Stop Plate Assembly

and Vapour Control Valve

When the control knob is pushed in, the dial drive plate disengages from the zero position dial stop (which prevents knob rotation in the zero (off) position), and opens the closing mechanism by pushing on the shaft assembly (see 3.2.4).

The stop plate is now disengaged from the dial stop and it is free to turn anti-clockwise. A drive screw produces movement of the vapour control needle valve within the needle housing, altering the size of the orifice available for the passage of vapour.

3.2.3 Dial Stops

The dial stop (zero position) prevents rotation of the knob assembly in the zero position.

3.2.4 Cut-off Mechanism

When the control knob assembly is in the zero position, the spring-loaded cut-off valve is closed. This prevents gas flowing into the vapour chamber.

When the control knob assembly is pushed in, the closing mechanism shaft pushes a spring loaded seal off its seat on a spool assembly. Gas is then able to flow into the vapour chamber.

3.2.5 Interlock Mechanism

With two or three interlocked vaporizers on the anaesthetic machine back bar, initial operation of the concentration control dial, by pushing on, activates the interlock system. The interlock push rods move outwards, ensuring that only that vaporizer can be in use at any time. The interlock deactivates as soon as the control dial is returned to the zero position.

DESCRIPTION

Selectatec Interlock

3.3 Temperature

Compensator (TC)

This device alters the resistance to the flow of gas passing through a bypass valve. The temperature sensitive element comprises a bimetallic assembly that expands/contracts with increase/decrease in temperature, causing the bypass plate to move away from, or towards the TC base.

At low temperature the bypass resistance is increased, forcing more gas through the vapour chamber to compensate for the lower vapour pressure of the liquid. At high temperatures the

reverse is effected.

3.4 Wick Assembly

The large wick assembly consists of a long strip of wick material attached to a metal backing strip, and rolled into a spiral. This forms a single unit cartridge assembly for ease of replacement.

DESCRIPTION

3.5 Filler Systems and

Agent Level Indicator

3.5.1 Agent Specific (Keyed) Filler

This unit is designed to be used with a bottle adaptor only - refer to the vaporizer user manual. Bottle adaptors for each agent type are available - see section 10, in the user instruction manual.

3.5.2 Screw Cap Pour Filler

This unit has a screw-plug, sealed filler opening.

3.5.3 Quik-Fil Filler

This unit is designed to be used with an agentspecific nozzle, permanently attached to the agent bottle. When the nozzle is inserted into the filler block, a valve opens inside the filler block. When the nozzle is pressed further into the filler block, a valve in the nozzle opens and agent

flows into the vaporizer. The filler block utilises an air lock which automatically stops the filling process at the maximum fill position. The vaporizer is drained through a separate valve in the base of the filler block.

3.5.4 Agent Level Indicator

The level indicator is a glass tube with maximum and minimum fill level marks printed on the glass. Provided the vaporizer is upright, with the control knob set at zero, the chamber cannot be overfilled as the design of the air escape ports facilitates air trapping at the maximum safe level. On agent specific (keyed) filler models, an overfill hole drains excess agent from the filler system. On screw cap filler models, a drain hole is included in the side of the filler block to drain the filler funnel level should excess agent be tipped into the filler block during filling.

DESCRIPTION

4. SPECIFICATION

4.1 Physical Dimensions

Width Height Depth

Cagemount 133 219 158 Selectatec Compatible with Interlock 120 242 190 Drager 'plug in' Compatible 100 242 190

Dimensions given above are in millimetres

NOTE The figures for Depth relate to Key Filler (Agent Specific) and Quik Fil models.

To calculate the depth dimension for Screw Cap Filler models, subtract 11 mm from the figures given above.

4.2 Weight

Approximate weight: 4.8 kg.

4.3 Capacity

Volume at MAX mark 250 ml (nominal) Volume at MIN mark 35 ml (nominal)

NOTE After draining, approximately 60 ± 10 ml of liquid is retained by the wick.

4.4 Filling System

Key Filler (Agent Specific)- Use with corresponding agent specific filler adaptor, see section 10 (USER

Manual), Ordering Information.

Pour Fill (Screw Cap) Quik Fil - Sevoflurane only -

Use with corresponding agent specific bottle.

4.5 Control Dial Scale

The control dial is marked as follows:

From 0 to 2% vol, by intervals of 0.2% vol

From 2% to maximum, by intervals of 0.5% vol

The control dial is marked '0' at zero

4.6 Patents

The Sigma Delta is protected by UK and foreign patents.

4.7 Temperature Range

Operating Temperature Range 15 to 35oC (58 to 95oF)

Storage Temperature Range -20 to 50oC (-5 to 122oF)

Storage in Transit (up to 7 days) -40 to 60oC (-40 to 149oF)

4.8 Flow Range

Operating Flow Range: 0.2 to 15 litres/min.

See section 7.4.1 (User Manual) for output accuracies at extreme conditions.

4.9 Pressure Range

Operating Pressure Range 0 to 5 kPa (0 to 0.7 psi)

Maximum Manifold Pressure 38 kPa (5.5 psi)

Maximum Test Pressure 38 kPa (5.5 psi)

5. SERVICE PROCEDURES

5.1 Service Policy

The Sigma Delta must only be serviced at an authorised service centre or by Penlon-trained technicians in accordance with the following procedure.

(a) The calibration should be checked periodically under

controlled conditions and a leak test performed. Detailed information on the use of the Riken Analyser is given in the following pages. Record the measured values in section 11 in the vaporizer user manual.

(b) Successive sets of figures should be compared to

determine if performance is deteriorating. Should deterioration be detected, a service should be carried out to restore normal operation.

(Halothane models - 5 years) to maintain performance within the specification.

(d) The Selectatec compatible vaporizer locking system

should be inspected during the vaporizer calibration test, and if damage to the locking shaft is suspected, the device must be referred to a Penlon certified engineer.

(e) Interlock system vaporizers -

function test the interlock system during the vaporizer calibration test.

(d) Quik-Fil system - at regular intervals (3 monthly

minimum, 6 monthly maximum), filling and draining must be checked under controlled conditions

NOTE The user must accept responsibility for any malfunction which results from non-compliance with the above requirements.

Returning the Vaporizer for Service / Repair

The vaporizer must be drained and allowed to dry out before packing. Always use the original packaging, to prevent damage during transit.

Checking Vaporizer Output

Calibration Procedure using the Riken Analyser

The Riken Model 1F-18 is normally calibrated by the manufacturer for measuring up to 8% vol. Halothane or up to 9% vol. Sevoflurane, either in air or in oxygen. Service checks on the vaporizer must be performed with oxygen if the vaporizer is checked on an anaesthetic machine. Use air or oxygen if the vaporizer is checked in a test laboratory.

CAUTION

A) It is essential that the gas used during service checks is recorded, B) The reference cell of the Riken must be purged with the appropriate gas before measurements are made.

Agents

The Riken gas analyser measures the refractive index of the gases and vapours and, although normally calibrated for measuring halothane, the instrument can also measure other vapours if an appropriate correction factor is applied. To obtain the true concentration of gases other than halothane multiply the reading shown on the Riken by the correction factors given below.

Carrier Gas

The refractive index of oxygen is higher than that of air so that, (a) the unit must be re-zeroed if the carrier gas is changed, and (b) the scale must be adjusted by a correction factor, applied by multiplying the Riken scale reading to obtain the true concentration.

Correction Factors

Halothane in Air Riken:

Factor (using air) Factor (using O2)

Halothane 1 1.06 Enflurane 1.05 1.11 Isoflurane 1.06 1.12

Sevoflurane 1.05 1.10

Halothane in Oxygen Riken:

Factor (using air) Factor (using O2)

Halothane 0.95 1 Enflurane 0.99 1.05 Isoflurane 1 1.06 Sevoflurane 0.99 1.05

Temperature and Barometric Pressure

Calibration checks must be performed at a

temperature between 19 and 21oC.

SERVICE PROCEDURES

The correction factor is ± 1.5% of readings, which is negligible in view of the accuracy of the instrument. Temperature correction is therefore not required, but the temperature should be measured and recorded to ensure that the test is carried out within the specified range.

Changes of barometric pressure due to weather are not normally of significance and can be ignored.

Altitude can, however, have significant effects and the following correction factors should be applied when appropriate. The Riken reading multiplied by the stated correction factor gives the true concentration corrected to Standard Temperature and Pressure (STP).

Altitude Factor Barometric

pressure (for reference)

600 m 0.9 910 mb

(2000 ft)

1200 m 0.85 850 mb

(4000 ft)

1800 m 0.8 813 mb

(6000 ft)

Method of reading the Riken Analyser

1. Readings may be taken from a tee-piece connected to the common gas outlet of the anaesthetic machine. An AGS system must be connected.

2. The sampling tube must be nylon or PTFE (which do not absorb vapours). Rubber sleeves may be used to make end connections but there must be minimal length of rubber exposed to the gases being sampled.

3. Sample by 2 or 3 squeezes of the hand bulb. Wait for fringe movement to cease before taking the reading.

4. After each resetting of the vapour control, time must be allowed for the output to stabilise. Suggested timescale: 2 L/min flow - wait 4 minutes 4 L/min flow - wait 2 minutes

8 L/min flow - wait 1 minute

5. a) The vaporizer must be half full, and rigidly supported in its correct operating position.

b) Temperatures must be stabilised for approximately 4 hours before checking c) The temperature must be in the range

19 to 21oC.

SERVICE PROCEDURES

Sample of Service Record Page

(see section 11 in the Delta User Manual)

Test Period 1 2 3 4

Vaporizer serial number:

Date:

Signature:

Print name:

Carrier Gas

Leak Test

(at 200 mmHg for minimum 60 secs)

Pressure must not drop below 180 mm Hg

Set Tolerance

0.0 0 - 0.1

0.2 0.14 - 0.26

0.6 0.45 - 0.75

1.0 0.8 - 1.2

3.0 2.4 - 3.6

*4.0 3.2 - 4.8

5.0 4.0 - 6.0

**7.0 5.6 - 8.4 **8.0 6.4 - 9.6 **7.0 5.6 - 8.4

5.0 4.0 - 6.0

3.0 2.4 - 3.6

1.0 0.8 - 1.2

0.6 0.45 - 0.75

0.2 0.14 - 0.26

0.0 0 - 0.1

4% Halothane vaporizer only

7% and 8% vaporizers only

Bypass resistance at 4 L/min

5.2 Workplace and Equipment

NOTE For complete safety when servicing this device, full reference must be made to the WARNINGS and CAUTIONS listed in section 1.

WARNING Adequate ventilation of the work area must be provided. During calibration procedures, connect the outlet of the vaporizer to an anaesthetic gas scavenging system that conforms to your national standards or regulations.

Environment - servicing must be carried out

in a stable temperature environment, preferably with thermostatic control or air conditioning, to maintain the temperature within 22°C ±1°C.

Gas Supply - flow check for bypass

resistance measurement must be carried out using air. Calibration after servicing must be carried out using oxygen.

Small tools - as listed throughout the

service procedures listed in this manual, and in the following pages.

Gauges, etc. - as listed in the following

pages.

Test Rigs - layouts and components are

listed in the following pages.

5.2.1 Standard Equipment

Pressure regulator 0 - 400 kPa (0 - 60 psig) Pressure gauge 0 - 400 kPa (0 - 60 psig) Pressure gauge 0 - 40 kPa (0 - 3000 mmHg) Pressure gauge or water column 0 - 10 kPa (0 - 100 cm H

2O)

Flow meter unit 0 - 10 L/min Pressure isolating valve Leak detection fluid

Torque driver 0 - 10 Nm

Gas analyser - The preferred form of

analysis apparatus is an interferometer. However, if used carefully, the following instruments are also suitable for a calibration check:

Infrared analyser Mass spectrometer

Molecular absorption meter The selected analyser should have a sensitivity better than ± 0.1%.

5.2.2 Test connectors and equipment (available from Penlon)

Pressure gauge tee connector 53196 Flexible hose with cagemount female

connector end 37019 Blanking plug with pressure gauge connector (Cagemount male) 37018 Nylon Catheter 52605

Exhaust tubing (22 mm diameter breathing hose) 57004

5.2.3 Special Purpose Service Tools and Equipment

(available from Penlon)

Test Connection Block 410579

Sample Tee Connector 53196

Blanking Plug with Pressure Gauge Connector 37018

Needle Housing Locknut Tool 410644

Small Wick Assembly Tool 410659

Needle Bal Seal Tool 410660

Interlock Checking Tool 410582

TC Assembly Tool (includes Bi-metallic

Strip Assembly Tool) 410647

TC Hinge Assembly Tool 410694

Dial Stop Setting Tool 410695

Closing Mechanism Removal Tool 410650

Interlock Bush Tool 408889

Needle Setting Tool 410602

NAD Interlock Tool 410772

5.2.4 Test Apparatus

Leak Test

- 5.2.4.1 (Test Apparatus A)

Flow Check for Bypass Resistance Measurement

- 5.2.4.2 (Test Apparatus B )

Calibration Check

- 5.2.4.3 (Test Apparatus B adapted for

calibration)

A schematic layout for each apparatus is given in the following pages.

SERVICE PROCEDURES

5.2.4.1 Test apparatus A

For leak testing

A - Air or Oxygen supply B - Pressure regulator 0 - 400 kPa (0 - 60 psig) C - Pressure gauge 0 - 400 kPa (0 - 60 psig) D - Flowmeter unit 0 - 10 L/min E - Vaporizer on Test connection block (410579) F - Blanking plug with pressure gauge connector (cagemount male) (37018) G - Pressure Gauge 0 - 40 kPa (0 - 300 mmHg)

Air or

Oxygen

Supply

Regulator

Pressure

Gauge

Flowmeter

Unit

Pressure

Gauge

Vaporizer

Blanking

Plug

SERVICE PROCEDURES

5.2.4.2 Test Apparatus B

Flow check for measurement and adjustment of bypass resistance

A - Air supply B - Pressure regulator 0 - 400 kPa (0 - 60 psig) C - Pressure gauge 0 - 400 kPa (0 - 60 psig) D - Flow meter unit 0 - 10 L/min E - Pressure gauge or water column 0 - 100 cm H

- Sample connector tee (53196)

- Vaporizer mounted on Test connection block (410579)

NOTE While the bypass resistance is being measured, nothing must be attached to the outlet of the vaporizer.

Air

Supply

Regulator

Pressure

Gauge

Flowmeter

Module

Pressure gauge

or Water Column

Vaporizer

(mounted on test connection block 410579)

Vaporizer must be in the OFF position

In Out

Sample connector

tee (53196)

SERVICE PROCEDURES

5.2.4.3 Test Apparatus B

Adapted for calibration test

A - Oxygen supply B - Pressure regulator 0 - 400 kPa (0 - 60 psig) C - Pressure gauge 0 - 400 kPa (0 - 60 psig) D - Flowmeter unit 0 - 10 L/min E - Vaporizer mounted on Test connection block (410579) G - Exhaust tubing (22 mm diameter breathing hose)

- Sample connector tee (53196)

Oxygen Supply

Regulator

Pressure

Gauge

Flowmeter

Module

Vaporizer

Analyser

Flow to

scavenge

system

Sample connector

tee (53196)

5.3 Pre-Service Checks

5.3.1 Leak Test and Bypass Resistance Measurement (Before servicing)

NOTE:

Anaesthetic gas scavenging equipment must be connected during these tests.

1. Drain the vaporizer and discard the contents - see section

5 in the vaporizer user Manual. Do NOT reuse the anaesthetic agent. Close the filler system.

2. Check for leaks from the vaporizer:

Use Test Apparatus A (5.2.4.1),and set a pressure of 200 mmHg. Measure, and record the pressure drop after a minimum of 60 seconds.

3. Measure the Bypass Resistance:

Allow 4 hours for temperature stabilisation. Use Test Apparatus B (5.2.4.2) to measure, and record the vaporizer Bypass Resistance, using a flow of Air at 4 L/min.

SERVICE PROCEDURES

5.3.2 Fault Finding (Before servicing)

Fault Possible Cause Treatment Reference

1. Low or zero (a) Insufficient liquid in chamber (a) Refill / check level User Manual output at all indicator settings

(b) Leak to atmosphere from (b) Service 5.4

operating of closing mechanism

shaft

(d) Incorrect needle setting (d) Service 5.4

(e) Bypass resistance out of (e) Adjust 5.4

adjustment

(f) Wrong agent (f) Drain and dry User Manual

WARNING If Halothane has been used in a non-Halothane vaporizer, DO NOT USE that vaporizer until all traces of Halothane have been removed. To prevent the possibility of malignant hypothermia, the vaporizer must be completely disassembled.

(g) Leaking sight glass seals (g) Fit new seal 5.4 (complete service

not necessary)

(h) Damaged sealing counterbores (h) Fit new block 5.4 on Selectatec block

(j) Worn or damaged claws on (j) Fit new locking 5.4 (complete service Selectatec block locking shaft shaft not necessary)

2. Low output at (a) Contaminated wick (a) Renew wick as part 5.4 high setting of Service only

(b) Leaking wick sealing (b) Renew wick as part 5.4 washer of Service

3. Excessive (a) Worn, or broken vapour control (a) Return unit to Penlon variation in needle valve spring or authorised distributor/agent output, when the set (b) Jamming needle (b) Service 5.4 value required is selected (c) Loose needle drive (c) Service 5.4 (i) clockwise, and then (ii) anti-clockwise.

Fault Possible Cause Treatment Reference

4. Zero not obtained (a) Cut-off mechanism (a) Service 5.4

O-seals leaking

(b) Leak between seal (b) Service 5.4 assembly and spool

(d) Worn needle or seat (d) Service 5.4

(e) Jamming needle (b) Service 5.4

(f) Incorrectly adjusted needle (b) Service 5.4

and seat

5. High output (a) Bypass out of adjustment (b) Service 5.4

(b) Bypass control plate (b) Return unit to contamination Penlon, or authorised

distributor/agent

6. Agent leaking (a) Leak between TC cover and (b) Service 5.4 from base chamber

7. Air leaking (a) Leak between TC base and (b) Service 5.4 from base body during test

8. Air or vapour (a) Leak between valve block (b) Service 5.4 leak around and body valve block

SERVICE PROCEDURES

5.4 Service Overhaul

5.4.1 General Information

If the vaporizer fails the calibration test a Service Overhaul must be carried out.

NOTE

A service overhaul must be carried out at a maximum 10 year interval even if performance appears satisfactory. This is a mandatory preventive maintenance requirement.

Preparation

The vaporizer must be removed from the anaesthetic machine for this service. The vaporizer must be drained of anaesthetic agent and then dried - pass an air flow of 10 L/min through it with the control at maximum setting until all trace of vapour at the output port is eliminated. Check using an agent analyser.

Bypass Resistance Measurement

Measure and record the bypass resistance before and after servicing - see 5.3.1.

Service Area

These procedures should be carried out in a laboratory room at a temperature of 22°C ± 1°C, not varying by ± 1°C over the test period. Approximately 1 metre of bench space is required. A scavenge system for anaesthetic vaporizers should be in operation. A supply compressed air, dry and clean, at 0.6 bar (8.7 psi) should be available.

O seal Lubrication

Lightly lubricate O-seals / O-rings with PTFE based, oxygen compatible, lubricant. APPLY SPARINGLY.

5.4.2 Health and Safety

Cleaning - always comply with the local health and

safety regulations when using solvents to clean components.

Loctite Superlube - use sparingly.

Prolonged skin contact may cause irritation. Always follow the manufacturer's instructions when using this product.

SERVICE PROCEDURES

5.4.3 Service Overhaul

Procedure

CAUTION

Before servicing, always drain the vaporizer follow the instructions given in the User Manual. Do not invert the vaporizer until the wicks are removed.

Leak Test and Bypass Resistance

(See section 5.3.1)

Before dismantling the vaporizer: a) Leak test the vaporizer. b) Measure the bypass resistance.

Dismantling the vaporizer

Connector Block

1. Remove the four M4 cap-head screws

(1) and the connector block (2).

2. Remove the O-seals (3) (connector

block to valve block).

3. Remove the top label (4) and lid (5)

(M6 countersunk screw).

Dial Assembly

4. Remove the dial label (6), and

discard.

5. Remove the two M3 cap head screws

and dial assembly (7).

6. Remove the circlip (8) from the shaft,

and remove the dial drive (9).

7. Remove the dial bezel (10) - two M3

cap-head screws.

Selectatec

North American Drager

Drager

Cagemount

Dial Assembly

Connector Blocks

Interlock - Selectatec

8. Remove the interlock shaft (11) and spring

(12). Note - on Cagemount, Drager and North American Drager models a dial return shaft (plus spring) is fitted.

Interlock - Drager and North American Drager

9. Remove the interlock system components

(13).

Dial Stops and Closing Mechanism Shaft - All models

10. Remove the dial ‘zero’ lock screw (14)

11. Remove the closing mechanism shaft (15).

12. Remove the dial ‘max’ stop (16).

SERVICE PROCEDURES

Drager Interlock

North American Drager Interlock

Selectatec Interlock Shaft, Dial Stops and Closing Mechanism Shaft

+ 71 hidden pages

Penlon Sigma Delta Service manual

Specifications and Main Features

Frequently Asked Questions

User Manual