Blow gun for air compressors

A blowgun is an air tool designed for use in many industrial applications where compressed air for cleaning purposes is used. Blowguns can be purchased with many tip configurations for many possible applications. However, the most important factor in choosing the right blowgun is SAFETY. Mostly it is common sense. You should always wear saftey glasses like you would with any other air tool. Safety includes the following considerations: PSI (force), noise level, and ergonomics. Safety Standards for PSI and noise level are outlined in the following US Department of Labor, OSHA Standards For General Industry Revision 1999:
Standard 1910.242(B) – Compressed air for cleaning purposes shall not exceed 30 pounds (13.5 kilograms) per square inch (6.5 square centimeters) when the nozzle end is obstructed or dead-ended, and then only with effective chip guarding and personal protective equipment.1
Standard 1910.95(a) – Protection against effects of occupational noise exposure shall be provided when the sound levels exceed those shown in Table G-16 of the Safety and Health Standards. Feasible engineering and/or administrative controls shall be utilized to keep exposure below the allowable limit.1

Filter,regulator, and lubricator for air compressors

In today's tough work environments filtered, regulated, and lubricated compressed air is essential in all industries and applications. Using all three of these methods will extend the life of your air tools, impact wrenches, pneumatic controls, pneumatic valves, etc., reducing maintenance and downtime costs. Failure to use properly filtered,regulated and lubrication will
cause equipment damage or possible injury.

Below are brief descriptions of each component:

Filter - Removes liquid, ,moisture or oil aerosols and submicron particles from a compressed air line before it reaches your air tool.

Regulator - Regulates the compressed air. Provides pressure regulation for the various requirements for air tools, impact wrenches etc. The variety of sizes and designs increase accuracy for the particular application.

Lubricator - Dispenses lubrication to air tools, impact wrench. Most air tools require lubrication to run at peak efficiency. Lubricators can provide constant lubrication according to factory recommended specifications reducing maintenance and downtime costs.

Calibrating your air tool

You need to calibrate your air tool regularly because mechanical parts wear out, contamination, lubrication runs out and general abuse. Most manufacturers have strict procedures requiring the periodic calibration of air tools. Normally calibration is required at least once a year. Ingersoll-Rand recommends every 6 months or 100,000 cycles.

Quick disconnects for air tool hoses

Quick disconnects offer an easy way of connecting pneumatic lines to your air tool and air compressor. The operating principle for sleeve type couplers is pretty simple. When the sliding sleeve on the coupler is retracted, internal locking balls are released, permitting the connector to be inserted or removed. The body size and flow capacity of quick disconnects generally corresponds to the inside diameter of the hose with which they are used. Most quick disconnects are very reliable and the designs have been around for awhile. Have several hoses around can sure make like a lot easier. Especially when you have to reach that really difficult spot with your impact wrench. Also remember there is always pressure loss along the length of the hose. The longer the hose the more pressure you are going to lose.

Impacts and torque control

Impact wrenches basically have to different types of torque control.

Conventional impact wrenches provide a torque output setting, but it is really up to the operator to determine when a nut is tight enough. These are some of the more common air tools found in the workplace.

Torque control impact air tools will shutoff at the predetermined torque setting. They are built for jobs that require accurate tightening. They incorporate built-in or detachable torsion bars. Based on their diameter and degree of adjustment, the torsion bar senses a predetermined torque level, and mechanically signals an internal shut-off device to prevent over-torquing

Choosing the right air compressor for you air tools - Duty cycle

One of the more critical aspects of air compressors is the duty cycle. It is also one of the least understood. Simply stated it is how long the compressor actually runs. It is described using a percentage and tells you how the unit runs during a certain amount of time. For example, if you have an air compressor rated with a 50% duty cycle, the compressor will run for 10 minutes in a 20 minute period. If the operator exceeds 50%, you can damage the unit. Most hardware store compressors are rated at 50% duty cycle and industrial units are rated at 75% and higher. In a nutshell the higher the duty cylce the more production you will get out of your air tool. For the garage hobbiest, 50% is probably ok. But if time is money, consider investing in a higher duty cycle. Also consult the specifications from your air tool manufacturer for more information.

Choosing the right air compressor for you air tools - Belt or Direct drive?

Basically a belt drive is what you want to run your impact wrench or air tool. Cheaper units all employ a direct drive system that runs at lower RPMs. Direct drives are directly connected to the motor. Therefore they are limited to running at the same RPM as the motor. Some motors run at higher RPMs to produce more air, however you will soon run it into the ground. Also, they are so loud that you can hear it in the next county. A belt drive compressor is the better alternative most of the time. A belt drive allows the pump to move a lot slower than motor. This translates into longer life. I would recommend an oil lubricated, belt drive compressor. However if need a smaller unit that is easier to transport, you may have to go with a direct drive model.

Choosing the right air compressor for you air tools - 1 or 2 Stage

There is a lot of confusion about single or two stage compressors. Is a 2 stage better than a single stage?

Again, it comes down to application and how much you are going to use your air tools. Also, how much pressure you really need will factor into your decision. Here are the basics. In a single stage compressor, the cylinder pumps air straight into the tank. In a two stage compressor, the first cylinder pumps the air into the second cylinder at about 90 psi. Then the air is pumped into the tank at about 175 psi. So you really only need to buy a 2 stage if you need the higher pressure. For most jobs a good single stage is fine for you air tools or impact wrench. You are better off buying a good single stage that a cheap 2 stage from your local hardware store.

Choosing the right air compressor for your air tools - Tank Size

The next factor to consider is tank size.

Tank sizes are generally stated in US gallons. For example, 30 gallon is a common tank size. So the question remains, how large a tank do I need? First of all, don't confuse a large tank with more run time for your air tools. If you use your impact intermittently, a large tank is fine. However if you have need for continuous use, you will need a small tank with big enough pump and motor. If the pump and motor are powerful enough, you shouldn't run out of air. You can save some dollars by purchasing an air compressor with a large tank and smaller motor for intermittent use. If you need to run a 1" impact wrench (about 20 CFM) intermittently, and have a small compressor with a large tank, you might have enough air stored in the tank to do the job. However, if you are constantly running your air tool, you will need to invest in a more powerful air compressor to do the job.

Choosing the right air compressor for your air tools - CFM

The next rating criteria for air compressors is CFM.

CFM stands for "cubic feet per minute". It is a measurement of volume. Basically it is how much air is being moved. Air tools require a certain amount of air to run on. PSI is just part of equation. Don't be confused by different CFM ratings at different pressures. Every manufacturer is trying to make their product look better by giving higher CFM ratings at different pressures. The only real concern is how much CFM you will get at 90 PSI. Remember 90 PSI is what most air tools require to operate. To find out what your air tool needs to run, just look on the box for the manufacturers specs. Generally, air tools require 4 - 6 CFM. A good rule of thumb on air compressors is you should get 3 -4 CFM per real HP at 90 PSI.

Choosing the right air compressor for you air tools - PSI

The next consideration when purchasing a new air compressor is, "How much PSI will I need?"

For the newbies, PSI is short for "pounds per square inch" and this is how most compressors in the US are rated. In Europe, you will see them measured in bars. PSI is all you need to worry about on this side of the Atlantic.
Most of the commonly used air tools require about 90 PSI to operate correctly. However, you will still need a compressor with a higher shut-off pressure. Most air compressors that you find at the local hardware giant are "single-stage" and shut off at 125 - 135 PSI. Don't let that fool you. You might think all you need is 90 psi, so that should work just fine. Generally, these light duty compressors shut off at 100 psi and don't forget about pressure loss in the line. The little light duty compressor will barely run an impact.It might be fine for light duty garage use, but if you really intend use your air tool, more is definitely better. Many industrial compressors are "two-stage," which means they build up to shut-off pressure in two stages. The first stage builds to about 90 PSI and the second stage builds to 175 PSI.

Choosing the right air compressor for your air tools

In the next few posts, I will give you a brief overview for selecting the right size air compressors to run your air tools.

The first topic will be horse power and how they are rated.

First of all, all horse power ratings are not created equal. What I mean is, you go to your local giant hardware retailer to pick out a new air compressor to run your impact. They have a 5 hp unit that is priced really cheap. Why is that 5 hp industrial unit cost so much more? 5 hp is 5 hp, right? Wrong.

Let me explain. Look at how much power the hardware store unit draws. It probably needs around 15 amps from a normal 110 volt circuit. At this rating,you are really getting only 2 hp. The 5hp rating on the box is inflated. To really produce true 5 hp you need at least 24 amps from 220 volt circuit to get it. If you are looking for 5 hp electric compressor, buy the industrial unit and stay away from the cheaper unit at your local hardware store.

Proper pressure for air tools.

A common question most people have is "How much air pressure does my Ingersoll Rand air tool need to run properly?" Air pressure at the tool should be no lower that 90 psi and no higher that 100 psi. Remember to figure some loss of pressure down the air hose. The critical factor is air pressure AT the air tool not the compressor.