- Cleans their seats of potentially damaging particles (Sand / Dirt / Swarf / weld slag)
- Stops debris from getting stuck between seats if administered before pigging pipeline
- Prevents and removes stiction (Torque to operate reduced / less strain on stem and actuator)
- Preserves the life of their seals, and components against mechanical and corrosion damage
Our Secret To Pipeline Ball Valves...
Pipeline Ball Valves are manufactured and tested in accordance with the requirements of API 6D, and are designed not to rely on lubricant to ensure that they seal.
During manufacture and factory testing, the use of lubricants and/or sealants is prohibited. This is to prevent masking of any defects in the new valve.
Installation and commissioning into a pipeline is an interventive engineering process, making use of hot and cold working techniques relying on mechanical tooling. As a result it is inevitable that between valve installation and commissioning, an amount of foreign debris will enter the valve (i.e. sand / dirt / swarf / weld slag). This is a natural result of the manufacturing process that cannot be avoided.
Once installed the valve is usually cycled during the testing of its gearbox or actuator, and again during hydrostatic testing of the pipeline.
These activities create tiny scratches on the polished ball surface where the debris present in the line wears on the ball and seat during the cycling of the valve.
In time, this reduces the valves ability to provide an adequate seal, as these tiny scratches begin to cause minor leak paths. All fluid and gas flows contain an element of contaminant which contributes to this effect over the life of the valve.
Minor leak paths that seal at low pressure become obvious when using the valve to isolate high pressure gas. Seating material is often softer than the ball itself in order to provide a pliable material which takes up minor leak paths, but at higher pressures the gas compresses the seats and they become less pliable meaning that the minor leak paths become more significant at higher pressures.
This type of damage mechanism can also be said to be true for gate and plug valves, as gate and plug surfaces are also susceptible to the similar damage. In fact any sealing surface subject to mechanical friction is susceptible to the damage mechanism described above.
Lubricants, lubricant-sealants and emergency-sealants
Lubricants help clean valve internals, and reduce operating torque. Valvecare use a light lubricant called Equa-Lube Eighty from Sealweld immediately after hydrostatic testing of valve, to purge all test water from seat pockets where corrosion normally occurs. The advantage of this is that it removes as much debris as possible from the internal mechanism of the valve, thus reducing the chance for wear. Lubrication also reduces the friction between the wearing surfaces. Of course, new contaminant can be introduced at any time via the flow in the pipeline.
Lubricant-Sealants help to preserve seat sealing effectiveness, and to seal worn valves with minor leakage problems. Valvecare use a lubricant-sealant called Total-Lube # 911 from Sealweld, this has been proven to seal minor scratches to sealing surfaces and shallow corrosion pits, as well as small nicks and cuts on soft seals.
For valves with sealing surface scoring, this is an effective way to achieve a bubble tight seal on a valve that would otherwise fail a leak test. Use of lubricant-sealants can delay or prevent the need for costly overhaul of a worn valve.
Emergency Sealants provide an effective temporary means of creating of leak tight seal, even on valves with severe leakage problems. Valve sealing plays an important role, when performing pipeline repair, modification or renewal work, as often the costs of shutting down, evacuating, draining, and excavating pipeline equipment are typically many times more than just the cost of a new valve. Valvecare use a Valve Sealant called Ball Valve Sealant #5050 from Sealweld, containing particles of PTFE, and is capable of sealing relatively large scratches to sealing surfaces.
Lubrication is introduced into the valve, using the seat injection fittings. Valves that do not have seat injections fittings can usually be retrofitted to include these. Specialist valve maintenance companies, such as Valvecare, can advise you on specifics for individual valves.
Seat lubrication, is a proven means of cleaning foreign debris from valve seats, and done properly as part of a scheduled valve maintenance programme, stops debris from getting there in the first place. This practice significantly reduces damage suffered during installation, commissioning and normal cycling operation, extending the service life of the valve dramatically. The costs associated with a scheduled maintenance program including lubrication are considerably lower than a full overhaul or replacement of the valve itself.
Lubricating your valves gives the following operational advantages:
* Cleans their seats of potentially damaging particles (Sand / Dirt / Swarf / weld slag)
* Stops debris from getting stuck between seats if administered before pigging pipeline
* Prevents and removes stiction (Torque to operate reduced / less strain on stem and actuator)
* Preserves the life of their seals, and components against mechanical and corrosion damage
These advantages reduce operational cost and should therefore form part of your planned valve maintenance programme.
Emergency Sealing involves the introduction of heavy sealant, through the valve seat injection fittings, to achieve a temporary seal. Valves that do not have seat injections fittings can usually be retrofitted to include these. Specialist valve maintenance companies, such as Valvecare, can advise you on specifics for individual valves.
Emergency Sealing your valves:
Provides an temporary bubble tight seal, even on valves with severe leakage problems
Has significant cost savings, when compared to alternatives
Saves time, with lead times for some replacement pipeline valves taking several months
The Lubrication, lubricant-Sealant and Emergency Sealant process involves the use of specialist equipment, capable of pumping a range of lubrication and sealant types safely at pressures of 10,000–15,000 psi. It is recommended that trained valve service engineers, proficient in the safe use of sealant guns and pumps, carry out this procedure.
Lubrication and sealing becomes more critical in applications such as Natural Gas, Production Wellheads, Gathering Systems, Gas processing Plants, Pipelines, Gas Storage Facilities and Gas Distribution Systems. Applications like these are more likely to cause damage to the critical sealing surfaces of valves, due to the lack of lubrication present in dry gas, and the presence of sand and debris in production wellheads. As part of a valve maintenance programme, preventative valve maintenance helps minimises the adverse effects of these services, increasing the service life of your valves.
For increased valve service life, the presence of an emergency seat sealant injection feature is an important consideration when procuring pipeline valve stock.
Equally as important is the choice of injection fittings and/or adaptors that are installed on the valve. Sealant injection fittings feature a means of passing sealant or lubricant into the valve, and incorporate a high pressure metal seated check valve. As a safety precaution, Valvecare do not endorse the use of carbon steel, crimped style injection fittings. As standard, we only recommend the use quality stainless steel injection fittings incorporating a threaded spring retaining cage, in order to minimise the risk of dangerous fitting failure.
Valve lubrication and sealing is an essential part of an effectively managed valve maintenance programme. Once installed and lubricated, a regular documented lubrication schedule should be established for all critical valves. Valvecare specialise in a supplying a total management programme for your valves, with a focus on the criticality of valves in relation to impact on safety elements and production, maintenance routines, spares holding, valve tracking and selection procedures. This type of valve management programme is a highly effective way of optimising reliability and safety whilst minimising cost and downtime.