Norriseal No-Bleed Pilot Valve MIZER

The MIZER® No-Bleed Pilot Valve is the most cost-effective solution for converting high-bleed pneumatic controls to low-bleed operation. This device effectively stops continuous bleed operation between dump cycles, thereby reducing environmentally-concerning methane emissions, while allowing previously wasted gas to be sent to the sale line. Conservatively, user can anticipate 90% savings from recaptured gas based upon estimated cycle rates of the controls. 95-98% values may be achieved in some applications.

Bleed gas vs. vent gas

“Bleed” gas is defined as gas that bleeds to atmosphere between dump cycles. “Vent” gas is that gas which, after energizing the dump or control valve must be released to atmosphere, and is usually a small fraction by comparison to the bleed gas volume. It is because of the high bleed between dump cycles that the EPA discourages the use of high-bleed pneumatic devices to control liquid level and gas pressure. The MIZER® device actually stops the continuous flow of gas from these controllers, only allowing gas to flow to the controlled device (dump valve or control valve) when necessary. Therefore, the amount of potential gas savings is dependent upon (among other things) the initial bleed rate and the frequency of operation of the controller and valve. In other words, a separator unit that fills slowly and dumps infrequently is bleeding substantial amounts of unutilized gas pressure to atmosphere most of the time. All of this gas that is vented to atmosphere between dump cycles would be saved when using a MIZER® retrofitted controller. Likewise, if the controller is very active, dumping fluid frequently, the savings would be less, as more gas is being used to activate the valve. It should be noted that neither the MIZER® nor any other lowbleed device is capable of saving gas that has been used to energize the valve. This gas will always be lost after the valve cycles and the diaphragm and connection lines vent. If the lines are not allowed to vent the valve will not return to the original (usually closed) position.

Ease of installation

The Cemco and FMC Invalco level control versions of the MIZER® pilot valve installation is a simple and painless operation. In fact, unlike installing traditional no-bleed level controllers, which require breaking the process connection, the MIZER® pilot valve is installed by simply removing the operating gas pressure from the controller, installing the MIZER®, blowing out the supply line to keep it clean, reattaching the supply line and adjusting. Different controllers require different kits–some containing more parts than others. Retrofit kits for pressure controllers such as the Emerson/Fisher 4150 or 4160 are more complex and therefore the procedure is also more complex, possibly requiring shut down. But, no welding of new fittings, no new tubing, no new cabinet refits are required. The MIZER® installs in minutes – not hours or days as is the case with installation of any complete new controller. Last, but not least, the operator continues using the controller they already know and trust – no need to learn the operating quirks of a completely new control.