Technical Specification
API 682 – Plan 53A
The range of Flopac® SPA seal support systems include plan 53A seal flushing units that are typically used with arrangement 3 contacting wet seals (3CW-FB, 3CW-BB, 3CW-FF)
Plan 53A Description
Purpose
Plan 53A seal support systems provide a barrier fluid to cool and lubricate the in- and outboard seals. The barrier fluid is maintained at a pressure greater than the seal box to eliminate product leakage.
Operation
Plan 53A seal support systems are closed loop systems that use an external reservoir to provide a pressurised barrier fluid for the inner and outer seal of a pressurized dual seal arrangement.
During normal operation, circulation between reservoir and seal is maintained by an internal pumping ring. The barrier fluid is pressurised by introducing an inert gas (usually nitrogen) from an external source. A regulator is normally used to maintain a constant pressure that is greater than the process/seal chamber pressure. This will reverse the normal leakage. Now the barrier fluid will leak into the process instead, and product leakage is eliminated entirely.
Maintenance is limited to a timely refill of barrier fluid, while ensuring a constant and sufficient supply of nitrogen. Refer to notes/recommendations below.
Heat exchangers
In order to provide cool barrier fluid plan 53A seal support systems are often equipped with a cooler. The cooling capacity must be designed to cope with the seals heat generation and the heat soak.
Although natural air draught cooling is preferred, most plan 53A seal support systems are equipped with an internal liquid (water) cooler. The size of natural air draught cooling sections will often proof impractical. For the higher heat loads external water cooler or forced air blast cooler may be considered. Flopac can provide all. Please have a look at our cooler section to check our standard availability. Tailored solutions are available as well.
Instrumentation
A plan 53A should be equipped with a pressure indicating transmitter, a level transmitter and a level gauge to monitor the systems pressure and level. A temperature instrument could be considered if relevant. Provided the unit is equipped with an internal cooling coil one may also consider a cooling water sight flow indicator.
Notes/recommendations
Flopac provides a complete API 682 compliant package, including all the necessary appendages.
The operating principle of this seal plan accepts a certain leakage of barrier fluid into the process. Though little (typically 10cc/h and less), the compatibility of the barrier fluid with product must be verified.
The unit operates under pressurised conditions. A safe refill of barrier fluid – under pressurised conditions – requires specific equipment, usually referred to as topping-up / make up or refill units. Please refer to our section Make up units for further details.
The constant and sufficient supply of the pressurising inert gas is usually arranged for by the user. That includes the regulator. Flopac is happy to advise on further details and the appropriate regulator. Please contact our application department.
For most pressurised applications we would recommend a plan 53B instead of a plan 53A. A plan 53B is easier to operate, is better equipped to receive natural air draught cooling sections and does not rely on the sometimes limited (pressure) capacities of a plant gas network. Separating the gas from the barrier liquid also eliminates the potential worry of the pressurising gas dissolving in the barrier fluid.
Please contact Flopac for a more detailed advise on all topics related to Flopac® seal support system plan 53A. We will gladly assist.
Plan 53A Features
Plan 53A – main features
Pressurised by external gas source.
No product leakage.
Lubricates and cools the seals.
Clean barrier fluid film on inboard seal faces improves seal live.
Lubricates and cools the seals.
Circulation device needed.
Benefits of the Flopac Plan 53A
Wetted parts all SS316.
Flexible designs all properly engineered.
Reliable performance.
(API 682/ISO 21049) compliant.
Compact and lightweight configuration.
Plan 53A Features
Plan 53A – main features
Pressurised by external gas source.
No product leakage.
Lubricates and cools the seals.
Clean barrier fluid film on inboard seal faces improves seal live.
Lubricates and cools the seals.
Circulation device needed.
Benefits of the Flopac Plan 53A
Wetted parts all SS316.
Flexible designs all properly engineered.
Reliable performance.
(API 682/ISO 21049) compliant.
Compact and lightweight configuration.
Options
Alternative material selections for specific services.
Flexible designs to fit a specific location or available space.
High pressure designs (ANSI 600# / 1500#) for static designs up to 200 barg.
Additional temperature- or flow instruments to enhance monitoring facilities.
Addition of a barrier liquid circulation unit; to ensure circulation and to enhance cooling capacity.
Addition of an all stainless steel 5 ltr refill unit with 75cc/str handpump. (Other refill options available. Note: filling funnels should not be used!)
Plan 53A Solutions
Contact us
Address
Westelijke Havendijk 15
4703 RA Roosendaal
The Netherlands
Phone
info@flopac.com