A17.REV

COMBUSTIBLE GAS DETECTION SYSTEM

NOTE: FINAL DATE: APRIL, 1988.

NOTE: THIS SPECIFICATION CAN BE USED FOR COMBUSTIBLE OR TOXIC	GAS DETECTION SYSTEMS

Part 1 -	GENERAL

1)	SUMMARY

A.	System to continuously monitor atmosphere for flammable gases and vapors.

B.	System to activate warning or alarm when preetermined concentration levels are reached

C.	System to detect:

NOTE: SELECT AS APPLICABLE

1.	Gasoline

2.	Hexane

3.	Propane

4.	Butadiene

5.	Methane

6.	Hydrogen

7.	Oxygen

8.	------

D.	Control unit located in:

NOTE: SELECT APPROPRIATE OPTION HAZARD

1.	Hazardous area

2.	Nonhazardous area

E.	Section Includes:

1.

2.

F.	Products Furnished but not Installed Under this Section:

1.

2.

G.	Related Sections:

1.	The general provisions of the contract.

2.	Electrical specifications.

H.	Allowances:

I.	Unit prices:

1.	Sensor

2.	Sensor Cable (/ft.)

3.	Zero and Span Gas

J.	Alternates:

2)	REFERENCES

A.	Codes and Standards

1.	Sensor assemblies and/or control housing to be rated explosion-proof and suitable for N.E.C. installation in Class I, Groups B, C, and D, division 1 hazardous locations.

3)	SYSTEM DESCRIPTION

A.	Design Requirements:

1.	Air to be sampled by catalytic detector in sensor and combustible gases burned catalytically

2.	When catalyst temperature is increased, electrical resistance is to increase proportional to the combustible gas concentration. Output voltage is to be transmitted to control module

3.	Signal is to be translated into an analog readout of percent lower explosive limit (% LEL)

4.	When combustible gas concentration exceeds set limits, it is to activate warning light and alarm circuitry

5.	System to indicate.

a.	Malfunctioning sensor.

b.	Shorted cable.

c.	Loss of power.

d.	An under range reading of 15% or greater.

6.	When system goes into alarm, the folllowing shall occur:

NOTE: DELETE IF N.A. - IDENTIFY ALARM SETPOINTS

a.	Activate audio/visual alarm.

b.	Indication on AMCS.

c.	Start exhaust fans.

d.	Shut down power.

B.	Performance Requirements:

SELECT RANGE

1.	Analyzer shall be capable of measurement in the range of ______, or 0-100% lower explosive limit

2.	Analyzer zero drift - 1% full scale in 24 hours.

3.	Analyzer span drift _ 1% full scale in 24 hours.

4.	Analyzer repeatability - 1% .

4)	SUBMITTALS

A.	Product Data:

1.

2.

B.	SHOP DRAWINGS:

1.	Complete drawings and manuals.

a.	Description of operation.

b.	Technical literature.

c.	Data bulletins.

2.	Associated wiring diagrams.

3.	Fully dimensioned housing and mount drawings, including information on finishes

4.	Wiring routes, and types.

C.	Samples:

D.	Quality Control Submittals:

1.	Design Data

a.

b.

2.	Test Reports

a.	(1)

b.	(2)

3.	Certificates

a.

b.

4.	Manufacturer's Instructions

a.

b.

5.	Manufacturer's Field Reports

a.

b.

E.	Contract Closeout Submittals:

1.	Operation and Maintenance

a.	Provide four bound manuals to the engineer. Each shall contain printed operating instructions for all system functions whose format has been compiled specifically for system. Manuals shall contain "as built" schematic wiring diagrams of all systems, internal wiring diagrams of the control panels, schematic wiring diagrams of each equipment item, parts lists, and maintenance notes

2.	Data

a.

b.

3.	Warranty

a.	Guarantee system, in writing, against defects in workmanship and materials for one year after acceptance. During this time the entire system is to be kept in proper operating condition at no additional labor or material cost to owner

b.

5)	QUALITY ASSURANCE

A.	Qualifications:

1.

2.

B.	Regulatory Requirements:

1.

2.

C.	Certifications:

1.

2.

D.	Field Samples:

1.

2.

E.	Mock-Ups:

1.

2.

F.	Pre-Installation Conference:

1.

2.

6)	DELIVERY, STORAGE, AND HANDLING

A.	Packing and Shipping:

1.

2.

B.	Acceptance at Site:

1.

2.

C.	Storage and Protection:

7)	PROJECT CONDITIONS

A.	Environmental Requirements

1.

2.

8)	SEQUENCING AND SCHEDULING

9)	WARRANTY

A.	Special Warranty

1.

2.

10)	MAINTENANCE

A.	Service must be rendered within 24-hours of notification.

B.	The manufacturer of the major components shall maintain a replacement parts department and provide and recommend test equipment when needed. A complete parts department shall be located in a geographical proximity consistent with the most expedient method of shipping replacement parts. An ample stock of individual components and equivalent unit replacements shall be carried for as long a period as demand warrants. This period shall extend well beyond the normal life expectancy of the equipment.

C.	Extra Materials

1.

2.

Part 2 -	PRODUCTS

1)	MANUFACTURERS

A.	Mine Safety Appliances (MSA).

B.	General Monitors.

2)	MATERIALS

A.	Wire and Conduit

1.	In accordance with electrical provision.

2.	Sensor Cable Requirement: 3 Conductor, spiral shielded, gauge as required (minimum 18 AWG)

3)	EQUIPMENT

A.	Sensor:

1.	Sensor Types

NOTE; DELETE IF N.A.

a.	Combustible gas Sensor - The combustible gas sensor shall be the catalytic bead type. The sensor must have a demonstarated resistance to degradation by silicones and reduced sulfur gases (Hydrogren Sulfide).

b.	Toxic Gas Sensors - Toxic gas sensor shall be the electrochemical type. The sensor shall not require the periodic addition of ragents.

c.	Oxygen Sensor - The oxygen sensor shall be the electrochemical fuel cell type. The sensor shall not require the periodic addition of reagents

2.	Response time: typically less than 5 seconds to alarm at preset level of 40 percent with and input of 50 percent LEL methane

3.	Range: 0-100 percent LEL.

NOTE; RANGE MUST BE SPECIFIED IN PPM IF THIS SPECIFICATION IS FOR TOXIC GAS

4.	Accuracy: plus or minus 2 percent (0 deg F to 130 def F) minus 18 deg C to 54 deg C

5.	Operating temperature: (minus 40 deg F to 200 deg F) minus 40 deg C to 93 deg C

6.	Capability of installation: 5,000 ft. from control unit.

7.	Explosion proof housing.

8.	Life: minimum one year.

9.	Sensors shall be capable of complete on site calibration.

B.	Control Unit:

1.	Control unit shall be wall mounted, Nema 4,with hinged front door and window to view LED display (or rack mounted)

2.	Control modules shall be dual channel type with a three-digit LED readout display per channel and trouble, warning and alarm indicators per channel

3.	Three separate alarm setpoint levels shall be provided for each sensor. All setpoints shall be independently adjustable for any value in the range

4.	Power:

a.	115 volts, 50/60 hz.

5.	Analog signal: 4-20 MA, provided for each channel.

6.	Operating temperature: (0 deg F to 130 deg F) minus 18 deg C to 54 C.

7.	Relays: S.P.D.T., 5-amp contacts.

C.	Uninterruptible Power Supply (UPS):

1.	Capable of maintaining full operation of the system for not less than 1 hour

2.	Switchover shall be instantaneous and automatic upon failure of primary power source

3.	Batteries:

a.	Lead-calcium, rechargeable.

4.	General:

a.	Current limited with high/rate/float maintenance rate.

b.	To return fully discharged battery to 70 percent of charge within 12 hours

5.	Enclose in control cabinet.

D.	Audio/Visual Alarms

1.	High intensity flashing light and horn.

2.	Both components to be powered by DC voltage from UPS.

3.	Light protected by lexan lens.

4.	Horn output at 3.0 meters (ten ft): 95 DB or greater.

E.	Calibration Equipment

1.	Contractor shall provide a calibration kit with all necessary fixtures, tubing, and test gas to allow for a thorough test of system

2.	All calibration equipment shall be turned over to the owner following start-up

4)	COMPONENTS

5)	ACCESSORIES

6)	FABRICATION

A.	Shop Assembly:

B.	Shop/Factory/finishing:

C.	Tolerances:

7)	SOURCE QUALITY CONTROL

A.	Tests:

B.	Inspection:

C.	Verification of Performance:

Part 3 -	EXECUTION

1)	EXAMINATION

A.	Verification of Conditions:

2)	PREPARATION

A.	Protection

B.	Surface Preparation

3)	ERECTION

4)	INSTALLATION

A.	Provide required power wiring.

B.	Provide emergency power.

C.	Wiring to be concealed.

D.	As it is not practical to enumerate in these specifications all details of fittings and accessory equipment required for proper operation of the system herein described, it is understood that they will be supplied by the Contractor without extraa compensation.

E.	Electronic component models must have been commercially available for at least one year prior to bid

5)	APPLICATION

A.	Special Techniques

B.	Interface with Other Products

C.	Tolerances

6)	FIELD QUALITY CONTROL

A.	Tests

1.	Contractor shall provide the services of qualified vendor personnel to completely check and start-up system for a period of (1) full day.

2.	Submit to Owner and Engineer verification of testing. This shall include a summary of the testing procedure and the test results in typed or tabular form. System tested to verify:

a.	Specified monitoring of areas in accordance with the functional requirements of the system. This will include introduction of appropriate samples of span gas at each sample pick-up point

b.	Specified operation of control function.

3.	Owner and Engineer reserve right to witness any part of the testing.

B.	Inspection

C.	Manufacturer's Field Service

7)	ADJUSTING

8)	CLEANING

9)	DEMONSTRATION

10)	PROTECTION

11)	SCHEDULES