Deepwater natural gas drilling rigs are among the most difficult and dangerous places to live, to work, and to provide maintenance for flow control systems. Reliable, dependable valves are the top priority for operations and service teams alike. Every item in the flow control chain must perform perfectly in order to control flow in a safe and uninterrupted manner.
Downtime and maintenance costs must be kept to a minimum. Strict standards must be met for safety, corrosion resistance, and minimum volatile organic compounds (VOC). And stringent emission standards require zero leakage, both inline and into the environment.
The Challenge
A customer that was using a 3” flanged, class 900 RTJ valve with a light condensate flow medium asked to overcome a very high torque issue he was facing, caused by a high differential pressure across the valve while opening the valve to release pressure, resulting in a valve that was difficult to open, and, eventually, in a deformed, or, even worse, broken valve stem.
Habonim’s Solution
The Habonim team analyzed the flow case with the client’s engineers and suggested an optimal solution: equalizing the differential pressure before operating the valve by using a smaller ball valve as a built-in “bypass” of the main valve.
The team recommended a 3” high pressure, 27 series valve, fitted with a zero VOC HermetiX™ stem seal and an integral 1/2” bore ball valve to equalize the pressure. In this configuration, valve torque is reduced at maximum differential pressure from 300 NM to 60 NM.
The stem material was INCONEL 780, which can withstand at least 1000 NM of torque, far exceeding the relevant safety standards.
In the event of pressure buildup or side load, the flexible “X” shape of Habonim’s innovative and field-proven HermetiX™ stem seal creates a dynamic sealing arrangement, actively adjusting itself to prevent fugitive emissions.
Key Advantages
- Enhanced safety — Preventing the main valve from being opened under differential pressure. Habonim’s safety interlock ensures that the bypass valve is opened first, balancing the pressure on both sides of the valve. The safety interlock ensured that the main valve could be closed only after the small bypass valve is closed. For added safety, a main pipe locking device ensured that only qualified personnel with access permission can operate the valve.
- Simplified installation — Because Habonim’s integral bypass valve had the same face-to-face dimensions as the client’s old valve, it enabled simplified conversion to Habonim’s solution and reduced downtime.
- Easy maintenance — Being a 3-piece valve, the Habonim series 27 valve is also easy to maintain. The center piece can be removed with minimum effort, without requiring removal of the entire valve from the line.
Performance
Extensive experience in offshore platform service means that Habonim’s cost effective, safe and simple solutions are based on proven design and performance. Our solutions meet our customers’ most stringent accreditation and regulatory requirements.
