Retractable Pilots

Figure 1

The Retractable Pilot System by John Zink Company provides the long awaited pilot-access solution. John Zink's revolutionary Retractable Pilot System allows operators to safely access pilots at grade while the flare remains in operation.

Traditionally, accessing flare-tip pilots for inspection and maintenance has been impossible while a flare is in operation. Although ladders and platforms are often available to access the flare tip for maintenance, personnel are not safe accessing the flare tip while the flare is in service.

Now, with the John Zink^® Retractable Pilot System, users can lower a pilot to grade for maintenance and return the pilot when maintenance is complete. All raising and lowering of the pilot is done by personnel at grade, with or without the flare in operation.

What does it look like?

For a look at John Zink's Retractable Pilot System, refer to the diagram in figure 2. Then review the labeled components that comprise the system. "Y" pilot support, attached to the tip Mounting frame, attached to the tip Sheaves for redirecting winch line John Zink® pilot assembly Pilot carriage Messenger lines (stainless steel) Winch line (stainless steel) Tension spring Fuel gas line (braided 304 SS exterior and 321 SS interior), integrated cable containing ignition wire and thermocouple wire. Marine-grade hand winch Tension spring to anchor winch line How does it work? Retractable pilot operation is simple. Assuming the pilot is at grade, the following steps would raise the pilot. Attach pilot (4) to pilot carriage (5). Attach flex lines (9) to pilot. Turn winch (10) to raise pilot. Pilot carriage (5) rides messenger cables (6). Watch flex lines (9) to ensure they travel freely. Verify lines are free of kinks and bends. When pilot is in operation position, attach winch line to spring. Turn on gas and power to the pilot system. Ignite pilot. To lower the pilot, perform the above procedure in reverse.

Figure 2

Where can this system be used?

Figure 3

John Zink engineers designed the Retractable Pilot System with flexibility in mind.

The system can accommodate stack heights up to 600 ft (182 m), and can handle most types of flare tips. Our Retractable Pilot System can be used on a new John Zink brand flare system or with any other flare system currently in service.

How many pilots should be retractable?

On flare tips with more than one pilot, users must decide how many pilots should be retractable. However, air-regulation standards often dictate the minimum number of working pilots required for a given flare diameter. John Zink Company recommends using this required pilot minimum to identify the number of Retractable Pilot Systems for that flare. In general, space limitations around the flare tip can also dictate the maximum number of Retractable Pilot Systems installed around each flare.

Who can install the Retractable Pilot System?

John Zink Company strongly recommends employing Liberty Towers to install the Retractable Pilot System. Liberty Tower's experience in field installation as well as retractable systems will ensure that the installation goes as quickly, smoothly and safely as possible.

At a minimum, Liberty Towers must dispatch a consultant to every installation of a Retractable Pilot System. No warranty will be honored unless a Liberty Towers consultant oversees the Retractable Pilot System installation. Although actual installation times vary according to the job site and circumstances, typical installation times range from 5 to 15 days.

Will the stack need to be analyzed structurally?

One of the greatest benefits of our Retractable Pilot System is that additional structural loading on the stack and foundation is minimal. This is primarily because the pilot gas line and wiring are supported on the messenger cables. Although the messenger cables are attached to the stack, this loading on the stack has minimal impact to the structural integrity of the system.

Note: The minimal structural-impact advantage is not present on Retractable Pilot Systems that use a rail mounted to the side of the flare. The addition of a rail to the stack causes greater wind drag, which can compromise the integrity of the flare structure.

Are there special maintenance requirements?

The Retractable Pilot System design is engineered to minimize system maintenance requirements and ensure reliability. The construction and component materials have been selected to withstand the hostile environments experienced by flares. Since the Retractable Pilot System is a mechanical system, it should be operated at least once every six months to ensure all components are properly functioning properly.

Figure 4

What type of ignition system should be used?

John Zink offers the High-Efficiency Electronic Ignition Pilot (SM/FF) on our Retractable Pilot Systems. If an existing flare uses conventional pilots and a Flame Front Generator (FFG), John Zink recommends replacing the FFG with an Electronic Ignition Pilot. The buyer has the option to retrofit the existing FFG panel or have John Zink supply a completely new ignition panel with auto-relight.

Contact a John Zink representative for more Retractable Pilot System information.

John Zink Company, LLC
11920 East Apache
Tulsa, OK 74116
United States of America
+1-918-234-1800

email: info@johnzink.com