SAFETY USE OF GRINDING AND POLISHING MACHINES BASIC INFORMATION

How to use safely grinding and polishing machines?

Provide every grinding or polishing machine which generates dust with an efficient exhaust system or dust abatement system. The exhaust system should consist of a hood ducted to an exhaust fan in such a manner as to carry away the dust to a device whereby the dust is separated from the air and is prevented from entering the workroom.

All personnel engaged in grinding or polishing operations must wear suitable eye protection.

Properly mount grinding wheels, and where necessary, fit with a bush of suitable material between the wheel and the spindle. A guard of sufficient mechanical strength should enclose the grinding wheel.

It is necessary to prevent vibration, which can be caused by incorrect wheel balance, lack of rigidity in the machine, loose bearings or incorrect use of the work rest. Additionally, incorrect fitting of the belt fasteners for a belt-driven wheel may cause the vibration.

Provide an eye screen for hand-held work when using pedestal or bench-type grinding machines. The area of the screen should be large enough to discourage the operator from looking around it.

The screen should always be in place and maintained at an adequate transparency.

Every grinding wheel should be positioned so that when in use the plane of rotation is not in line with any door, passageway, entrance or a place where someone regularly works.

Finishing machines should be guarded with only the working face of the belt exposed and the belt should be mounted such that it rotates away from the operator wherever practicable. Before use the condition of abrasive belt should be examined and replaced if worn and the correctness of the tracking of the belt should be checked by rotating the belt by hand. 

If necessary the belt should be adjusted and finally checked with a trial run. Where possible suitable jigs

or fixtures should be used to hold or locate the work piece. 

The work piece should never be held in a cloth or any form of pliers and gloves must not be worn when using a finishing machine.

SAFE USE OF HYDRAULIC POWER TOOLS BASIC INFORMATION

How to safely use hydraulic power tools?

The fluid used in hydraulic power tools must be an approved fire resistant fluid and must retain its operating characteristics at the most extreme temperatures to which it will be exposed. The exception to fire-resistant fluid involves all hydraulic fluids used for the insulated sections of derrick trucks, aerial lifts, and hydraulic tools that are used on or around energized lines.

Do not exceeded the manufacturer's recommended safe operating pressure for hoses, valves, pipes, filters, and other fittings.

All jacks - including lever and ratchet jacks, screw jacks, and hydraulic jacks - must have a stop indicator, and the stop limit must not be exceeded. Also, the manufacturer's load limit must be permanently marked in a prominent place on the jack, and the load limit must not be exceeded.

Never use a jack to support a lifted load. Once the load has been lifted, it must immediately be blocked up. Put a block under the base of the jack when the foundation is not firm, and place a block between the jack cap and load if the cap might slip.

To set up a jack, make certain of the following:

• The base of the jack rests on a firm, level surface;
• The jack is correctly centered;
• The jack head bears against a level surface; and
• The lift force is applied evenly

All jacks must be lubricated regularly Additionally, each jack must be inspected according to the following schedule:

• for jacks used continuously or intermittently at one site - inspected at least once every 6 months;
• for jacks sent out of the shop for special work- inspected when sent out and inspected when returned; and
• for jacks subjected to abnormal loads or shock - inspected before use and immediately thereafter.

TOXIC GAS METERS BASIC INFORMATION AND TUTORIALS

What Are Toxic Gas Meters?

Toxic Gas Meters

Description and Application. 

This analyzer uses an electrochemical voltametric sensor or polarographic cell to provide continuous analyses and electronic recording. In operation, sample gas is drawn through the sensor and absorbed on an electrocatalytic sensing electrode, after passing through a diffusion medium. 

An electrochemical reaction generates an electric current directly proportional to the gas concentration. The sample concentration is displayed directly in parts per million. 

Since the method of analysis is not absolute, prior calibration against a known standard is required. Exhaustive tests have shown the method to be linear; thus, calibration at a single concentration, along with checking the zero point, is sufficient.

Types: Sulfur dioxide, hydrogen cyanide, hydrogen chloride, hydrazine, carbon monoxide, hydrogen sulfide, nitrogen oxides, chlorine, and ethylene oxide. These can be combined with combustible gas and oxygen meters.

Calibration.

Calibrate the direct-reading gas monitor before and after each use in accordance with the manufacturers instructions and with the appropriate calibration gases.

Special Considerations.

• Interference from other gases can be a problem. See manufacturers literature.

• When calibrating under external pressure, the pump must be disconnected from the sensor to avoid sensor damage. If the span gas is directly fed into the instrument from a regulated pressurized cylinder, the flow rate should be set to match the normal sampling rate.

• Due to the high reaction rate of the gas in the sensor, substantially lower flow rates result in lower readings. This high reaction rate makes rapid fall time possible simply by shutting off the pump. Calibration from a sample bag connected to the instrument is the preferred method.

PHOTOIONIZATION METERS BASIC INFORMATION AND TUTORIALS

What Are Photoionization Meters?

Description and Applications.
Ionization is based upon making a gas conductive by the creation of electrically charged atoms, molecules, or electrons and the collection of these charged particles under the influence of an applied electric field.

The photoionization analyzer is a screening instrument used to measure a wide variety of organic and some inorganic compounds.

It is also useful as a leak detector. The limit of detection for most contaminants is approximately 0.1 ppm.

Calibration. The procedure for calibration involves applying the
calibration gas (typically 100 ppm isobutylene) to the instrument
and checking the reading.

Special Considerations.
The specificity of the instrument depends on the sensitivity of the detector to the substance being measured, the number of interfering compounds present, and the concentration of the substance being measured relative to any interference.

Many models now have built-in correction or correlation factors. After calibrating the unit on isobutylene, select the gas to be measured.

The instrument will automatically correct for the relative sensitivity of the gas selected. Some instruments are listed by an NRTL for hazardous locations.

Check the operating manual for specific conditions.

Maintenance.
Keeping these instruments in top operating shape means charging the battery, cleaning the ultraviolet lamp window, light source and replacing the dust filter. The exterior of the instrument can be wiped clean with a damp cloth and mild detergent if necessary.

Keep the cloth away from the sample inlet, however, and do not attempt to clean while the instrument is connected to line power.

AIR QUALITY TESTING AND MONITORING METHODS OF SAMPLING

Indoor air quality testing may be necessary to ensure employee safety. Testing and monitoring may be applied to those conditions where employees may be exposed to:

nitrogen dioxide and sulfur dioxide
landfill gases
noxious odors
radon gas
factory emissions
odor complaints
rainwater
metals
smoke levels
dust
volatile organic compounds
indoor air quality (including Carbon Monoxide)

The results of air quality testing may be used to:
• Assign levels of worker respiratory protection
• For emergency planning

Methods of Sampling and Testing
Electric Power producers shall provide adequate means of carrying air monitoring in generator houses, transmitting stations, injection and switching substations, etc.

Three main methods are available to measure air pollution:

Passive Sampling: This refers to absorption or diffusion tubes or badges that provide a simple and inexpensive indication of average pollution levels over a period of weeks or months. Plastic tubes or discs open at one end to the atmosphere and with a chemical absorbent at the other, collect a sample for subsequent analysis in the laboratory.

The low cost per tube allows sampling at a number of points and is useful in highlighting "hotspots" where more detailed study may be needed. The quality and accuracy of the data from passive sampling tubes does not make them suitable for precise measurements but they can give useful long term trend data.

Active Sampling: This involves the collection of samples, by physical or chemical means, for subsequent laboratory analysis. Typically, a known volume of air is pumped through a filter or chemical collector for a known period of time - the collection medium is then subjected to laboratory analysis. This method is not suitable for continuous or near-real time air quality monitoring.

Automatic Sampling: This is the most sophisticated method of air quality analysis, producing high-resolution measurement data of a range of pollutants. The pollutants that can be measured include, but are not limited to, NOx, S02 CO, 03, VOCs, PM10, PM2.5, Carbon Black, Hg, Benzene etc. The air quality is continuously sampled and measured on-line and in real-time.

The real time data is stored, typically as one hourly averages, with data being collected remotely from individual monitoring stations by telemetry. Remote control of the monitoring and data system is also possible as is remote diagnostics for most of the analyzers.