Although the first-generation pulsejet design had proved to be successful, ValvTechnologies found an area where the product could greatly improve by working with their customers. The routine adjustments to the packing arrangement were observed to be difficult, dangerous and improperly executed. This could cause the packing to unevenly and prematurely wear. Partnered with our customer, ValvTechnologies commenced a program to develop a solution which could make the entire four months (125,000 cycles target) without a need to adjust the packing.
This would reduce the number of times employees were in harm’s way and reduce volatile emissions into the environment. When ValvTechnologies began this endeavor, they needed a measurement criteria for stem leakage. We decided to utilize one of the most common and widely accepted fugitive emissions tests, ISO 15848 for measurement. When developing our test, we had to make some test modifications because even ISO 15848 did not effectively simulate the test they were performing.
After partnering with several vendors and running through many iterations of product design, the Special Projects team at ValvTechnologies came up a configuration which greatly exceeded the results we were seeking. Through painstaking efforts, the team was able to employ special materials, coating technology and a unique seal combination of filled PTFE, PEEK and graphite (known now as EcoPack®) to allow our customer to make it to an eight-month turn-around plan.
In late 2015, ValvTechnologies announced the offering of the EcoPack® technology which has been specifically designed for high-cycle applications of over 250,000 cycles without adjustment. The EcoPack® technology is a stem-sealing solution designed to seal at line temperatures of up to 450°F (232°C). The assembly is tested to be fire safe and shows excellent compatibility with syngas.
The EcoPack® design does not require traditional live-loading utilizing spring discs, therefore, the gland is held stationary and flush with the bonnet. This solution means the packing does not require adjustment during operation, reducing site safety concerns and need for continual maintenance. This design uses pressure from the process to provide adjustment with an integral spring load for low pressure. The EcoPack® system has been introduced in the ValvTechnologies, NexTech® 2nd generation pulsejet valve, a two-piece trunnion mounted ball valve. Through successful lab testing as well as field tests well in excess of anything before achieved in this service, ValvTechnologies now has multiple installations utilizing this sealing technology.
Throughout the course of the EcoPack® development, ValvTechnologies proved several design theories while we established new ones. We set out to develop a new type of stem seal and wound up engineering a superior sealing system.