The Three Million Dollar Drip
Mon, 03/09/2009 - 11:22am
At a large west-coast pharmaceutical plant a batch of a sophisticated injectable drug was in the fill/finish stage when something went wrong. The product was being pumped from a portable transfer vessel through a 90° hose connection at the base of the vessel. The connection was a standard 2-bolt high pressure clamp that bolted together metal-to-metal.
Nobody knows exactly what went wrong but the best guess is that the portable vessel was moved slightly after the clamp had been put in place. This movement turned the joint slightly, not enough for it to be obvious but enough to compromise the clamp's ability to maintain a seal. The two halves of the clamp met before they applied full pressure on the ferrules and the gasket a common occurrence with some low-cost clamps.
During the transfer process it was noticed that the connection dripped, though very slightly, and transfer was terminated. Had the drug being transferred been less sensitive and less stringently controlled, the result might have been limited to the loss of a few drops of product and the need to replace the faulty clamp.
In this instance, however, the drops of product and loss of a little production time were totally unimportant. The question was: Did any ambient air enter the transfer line through the break in the coupling? And, since it could not be proven to the FDA that outside air did not enter the process through the clamp, the entire batch, $3 million in value, had to be scrapped.
Needless to say, the plant's engineering staff immediately set out to find a way to prevent any such recurrence. The cost of a fix for this problem was secondary: security was the singular goal.
They succeeded when they located a source for a sanitary clamp perfectly adapted to this application, one that had already accumulated a long record of fault-free service. The clamp is one of a line of precision-made hygienic clamps from L.J. Star Inc., designed specifically for pharmaceutical and biotech applications. And the cost turned out to be only $92.15, per installation.
The clamp design utilizes a two-pin hinge that ensures uniform gasket compression and a unique groove profile to further improve clamping efficiency. Clamps are 316 stainless as standard with either domed hex nut or wing-nut closures. A wide range of sizes and options are available. In this case the L.J. Star applications engineer recommended a 2-inch model SH Type I clamp with an ergonomic standard wing-nut closure. The company purchased three of these clamps for immediate use, with more to follow. And, at last contact, high-value product was being transferred from portable vessels through these couplings on a routine basis with no problems encountered.