1 A ratio variable, has all the properties of an interval variable, and also has a clear definition of 0.0. 2  When the variable equals 0.0, there is none of that variable. 3  Variables like height, weight, enzyme activity are ratio variables.4  Temperature, expressed in F or C, is not a ratio variable. A ordinal variable, is one where the order matters but not the difference between values. 2  For example, you might ask patients to express the amount of pain they are feeling on a scale of 1 to 10. 3  A score of 7 means more pain that a score of 5, and that is more than a score of 3.
Also be sure a hole has not been punched in the bellows as this will cause a vacuum leak. The second thing that causes breaker to blow is simply an old worn out electric pump motor, especially in salt water applications. The third cause is that the holding tank is full and the vent line is plugged.
A propane tank explosion is a type of BLEVE, or Boiling Liquid Expanding Vapor Explosion. This type of explosion occurs when the pressure in the tank exceeds that which it can safely vent. Eventually, rising pressure will cause the tank to rupture and burst. Cause. A propane BLEVE occurs mainly when it is exposed to high temperatures, like a fire. The temperature heats the liquid propane inside the tank, causing it to expand to a point that the stress it places on the tank becomes too high. When propane gas leaks from the tank in a fire, it will ignite and can cause an explosion. Relief Valve. All propane tanks are equipped with a relief valve. When the pressure inside a tank rises, the relief valve opens and starts venting gas to bring the pressure down.