Eliminating Purged Gas

At PCS Nitrogen, an ammonia and urea plant, located in Trinidad West Indies, absorber feed pumps at an ammonia unit became the focus of one recent Action Team.

While participating in a Manufacturing Game® workshop a group of mechanics and operators discussing various defects realized that there was a variance in pressure on the absorber feed pumps. Purge gas is vented every time the absorber pressure on the pumps is high. There was a change in operating conditions that had not been reflected in the equipment.

At the time of the workshop, PCS Nitrogen had been experiencing venting of purged gas at a rate of once a month for four consecutive months. Every episode of purged gas was costing PCS $10,000. A mechanic had fixed this problem four separate times but no one had ever considered why it was happening. The cross-functional group was able to pinpoint the problem and come up with a solution in a matter of minutes.

The Team set a goal to eliminate the venting of purge gas and associated costs. They need to change the RU cold set pressure from 200 psi to facilitate the present (real) pressure and complete the Management of Change (MOC) process.

One of the workshop participants asked “shouldn’t we have caught this when the original change was made?” This is of course true of most defects. You can bet that this team will be much more aware of potential defects the next time there is a process change. One of the Team members when asked about lessons learned commented, “you can repeatedly look at a problem individually and not resolve it. As a cross-functional team definition and correction are possible.”