Valves are an important part of regulation in any system, and their seals are designed to be used in different types of engines for controlling oil consumption, and valve lubrication.The design and manufacturing of the seal is the key to ensure seal performance and longevity.
Valves have many uses and are found in virtually every industrial process, including water & sewage processing, mining, power generation, processing of oil, gas & petroleum, food manufacturing, chemical & plastic manufacturing and many other fields.
Some examples of valve seals include: ball valve seats, globe valve discs, stem packing, stem seals, valve discs, valve packing, valve seals, and valve stem packing.
Having a proper valve seal can save you thousands of dollars in repairs at the end of the day, so it's important to check them semi-regularly. For example purposes, we'll focus on cars, but this can be translated across a variety of systems and industries. Here are some symptoms of a bad valve seal that may need to be replaced:
One sure-fire way to tell if you have a faulty valve seal is to perform a cold engine test. When your vehicle has been sitting overnight or for a longer period of time, the top of the head of the valve cover will have some oil left over from the last time you drove. When you start the engine, the oil ends up getting sucked down through the bad seal into the combustion area, producing a blueish smoke out of the tailpipe. This may indicate that your valve is not securely sealed and that it’s time to get a new one.
Another way to test a bad valve seal is to be aware of what happens while your vehicle is idling. When your vehicle is stopped for a significant amount of time, high vacuum levels will cause the oil to build up around the valve system while it is closed. In a faulty valve seal situation, when you begin to accelerate again, this oil can end up getting sucked past the seal an into the valve guide. This causes more of this blueish smoke, due to the burning of oil, to come out the tailpipe.
High levels of oil consumption is another indicator that you have a bad valve seal. This is because oil is being leaked out or burned excessively and causing oil to decrease at a higher rate than normal. You can detect this loss of oil with a basic oil dipstick and keeping a regular log of oil levels. If no oil leaks can be found around the vehicle, you may still have a bad valve seal, as the oil will likely be burned up causing excessive smoke.
Another indicator of a faulty valve seal, as mentioned above, is the high presence of smoke. It’s common for some exhaust smoke to be present when you first start your vehicle, but if it begins to last longer than normal, your valve seal may be deteriorating. In addition, if you have a bad valve seal, the excessive smoke will tend to come in waves as an indicator of oil burning.
Engine braking is when other ways besides external braking are used to slow down your vehicle within an engine. When you have a bad valve seal, the oil that collects at the front cover of the head will end up burning when you push on the accelerator after coasting for a while. This is apparent especially when going downhill and again will be indicated by the excessive smoke that leaves the tailpipe. The oil here burns longer than in normal cases.
The final indicator of a poor valve seal is a lack of acceleration power. You can also perform a compression test to see if this is the case. A higher level of compression will indicate that it’s a valve seal problem, while a low level of compression will indicate a piston ring problem. These two areas can be very similar in their faulty symptoms so it’s best to be informed on their differences.
A badly designed seal can result in engine oil flooding, which can eventually cause a breakdown. Gallagher Fluid Seals understands the importance of a well-designed industrial seal and can help design a custom solution for you, or supply you with standard off-the-shelf seals from the world's top suppliers.
For more information about valve seals what why they fail, or to find solutions, contact Gallagher's engineering department.
The original article can be found on Real Seals' website.
A smooth running engine is all about timing. The modern combustion engine is made up of around 10,000 separate parts, all of which need to be in sync with each other –moving, opening or closing at just the right moment. Valves are an important part of this process, and without a functioning seal, they can’t do their job. A relatively simple part to replace, if a broken seal is left unattended for too long, vast amounts of damage can be done to the engine, potentially leading to eye-watering bills. So, the question is, how long do valve seals last, and what warning signs indicate they’re no longer doing their job.
An engine contains a lot of moving parts that require a lot of lubrication. Even so, it’s important that the oil that provides this lubrication doesn’t enter certain areas of the engine. Valve stem seals keep the oil within the crankcase and stops it from entering the combustion chamber and prevents the oil within the cylinder head becoming contaminated.
Valve seals are designed to last a long time under the right conditions, around 200,000 kilometres. Of course, you probably picked up on ‘the right conditions’ part of that sentence. Certain factors can have a significant impact on how long valve steam seals last, such as infrequent oil and filter changes, as we well as poor installation.
If a valve stem seal begins to fail, it’s important that it’s replaced as quickly as possible before profound damage is done to other parts of the engine. So, what are the signs of a bad valve seal?
Starting a cold engine is often a good way of determining the health of the valve seals. If your car has been sitting overnight or for a longer period of time, a film of oil, left over from the last time you drove, will be coating the head of the valve cover. When you start the engine, this oil will be sucked down through the failing seal into the combustion chamber, and bluish smoke will be expelled from the exhaust pipe. If you notice this, get your car checked by a trusted mechanic.
A similar phenomenon happens when idling. If you find yourself stopped for a period of time with the engine running, high vacuum levels can cause oil to build up around the valve seal. If it’s faulty, some of this oil will get sucked into the combustion chamber and bluish smoke, caused by burning oil, will be emitted from the exhaust pipe.
If your car’s exhaust continues to emit a lot of smoke throughout the journey and not just at the beginning or when idling, it’s an indication that the valve seals may be deteriorating. If the smoke comes in waves, it’s a sure fire sign that you need to get it checked.
As you can probably tell, if a valve seal is leaking oil, oil consumption must increase. One way to keep an eye on this is by using a dip stick and keeping a record of oil levels. If you find it dropping quicker than normal, the valve seals should be checked.
Engine braking is when you slow the car without the traditional means of the brakes. If you coast for a period of time, especially downhill, excess oil will collect at the top of the valve cover. When you press the accelerator, this oil can be sucked through a faulty seal, once again producing excess smoke.
Unfortunately replacing valve stem seals involves removal and dismantling of the cylinder head, which takes many hours and so labour costs are usually quite high, however recent developments by tool and equipment manufacturers have made it possible to replace these seals without the need to remove the cylinder head, slashing the time (and money) to replace them.
Faulty valve stem seals can be a minor issue – until it isn’t. They are an important layer of protection for vulnerable (and expensive) parts of the engine, so it’s important they are always functioning properly. If you pick up on any of the warning signs mentioned above, book in with our friendly team immediately before further damage can be done. To prevent issues associated with faulty valve seals, always make sure your engine’s oil levels are good and the filters are changed before they become clogged.