What are KST values?

KST Definition KST, the deflagration index of a dust, is a generalized number used to estimate the anticipated behavior of dust deflagration or explosion. It indicates a dust’s approximate explosive power compared to other dusts.

What is Pmax value?

The Maximum Explosion Pressure (Pmax) and the Kst of the dust sample tested is defined as the mean of the maximum values of each test series (total of 3 series) over the concentration range close to the observed maxima.

What is the deflagration index?

The measure of the explosibility of a dust cloud, in units of bar-m/s.

What are combustible dusts?

The combustible dust NEP defines combustible dust as a solid combustible material, composed of distinct pieces or particles, that “presents a fire or deflagration hazard when suspended in air or some other oxidizing medium over a range of concentrations, regardless of particle size or shape.” A number of voluntary …

How to test the KST value of dust?

The main explosion chamber is then evacuated to 0.4 bar absolute. An automatic test sequence is initiated to pressurise the dust container to 20 bar gauge, and then the fast acting valve on the dust container outlet is opened to allow material into the explosion chamber.

Which is more dangerous, high KST or low KST?

The higher a Kst value is the more “energetic” the dust is but that does not change the danger associated with dusts having a lower Kst. In fact, some of the most well-known dust explosion case studies come from St 1 class dust.

What’s the difference between KST and Pmax testing?

St 1 – KSt value less than/or equal to 200 bar-m/sec and greater than 0 St 2 – KSt value between 201 and 300 bar-m/sec St 3 – KSt value greater than 300 bar-m/sec

How to calculate the KST of an explosion?

From the tests, the arithmetic mean of the maximum values (both maximum pressure and maximum rate of pressure rise) is obtained. The Kst value is calculated as the equivalent pressure in a 1 m 3 sphere from the cube law (Kst value = cube root of volume x explosion pressure rise).