How to Size Your Compressed Air Supply Hose (Bull Hose) for Sandblasting
One key way you can improve your sandblasting production and reduce issues with your sandblasting is by properly selecting an air supply hose also known as a bull hose for your sandblast pot. This article will cover important tips to ensure you select a bull hose for blasting that will meet your needs effectively.
Tip 1 – Choose a large size Air Supply (Bull Whip Hose)
Ultimately the larger your air supply hose is for blasting the faster you can blast. However, there are certain recommended minimums you should consider so that you do not experience issues like pressure drop in blasting or pulsing of blast media which can be indicative of not having a large enough air supply hose for blasting. You should always try to size your bull whip hose for blasting so that the internal diameter “ID” is about 4 times the size of your blast nozzle. This will ensure you provide sufficient air volume at the appropriate pressure to maximize productivity. For every 1 PSI reduction in blast pressure your blast production can reduce 1 – 1.5% which means supplying adequate volume and pressure is key to achieving maximum blast production.
|Blast Nozzle Size||Minimum Suggested Compressed Air Line “ID”|
|¼” (No 4)||1”|
|5/16” (No 5)||1-1/4”|
|3/8” (No 6)||1-1/2”|
|7/16” (No 7)||2”|
|½” (No 8)||2”|
Tip 2 – Choose the right connections
A second thing to consider is that you will want to choose connections that do not restrict the flow of air. You will want to ensure your connection to the blast pot air inlet is designed to handle the high flow rates in CFM and pressures of blasting. You can have a great bull hose in size but then choose fittings that restrict volume and pressure of air flow which results in losing the benefit of the large blast pot air supply hose. So if you have a 1” ID blast hose make sure your bull whip hose fittings are 1” and connect to a 1” outlet on your compressor to ensure you don’t lose pressure.
Tip 3 – Limit Blast Pot Air Supply Hose Lengths
A third factor you want to consider is the length of the bull hose. Longer length air supply hose air pressures will drop as air travels through the line. While larger ID hoses will help reduce this drop, it can often be better to limit the length of the supply hose from the compressor to the blast pot and from the blast pot to your blast nozzle. Keeping your blast pot supply line length down will reduce pressure drop which as mentioned helps to keep sandblast production speeds higher.