How A Piston Ring Works In A Marine Diesel Engine

How A Piston Ring Works In A Marine Diesel Engine

What is a piston ring?

Piston rings are fitted to seal the gap between the liner and the piston. An integral piston part, marine piston rings play a pivotal role in ensuring that the diesel engine functions perfectly. They are produced and classified according to their purpose.

Piston rings in a marine diesel engine

Similar to other types of internal combustion engines, a marine diesel engine operates with three or more types of piston rings. The smooth and efficient operation of a marine diesel engine relies heavily on the secured sealing of the piston rings and liners.

Functions of marine piston rings

Compression gas seal – Compression piston rings guarantee that there is limited leakage, which can result in decreased gas compression pressure. A leak in gas compression will lead to insufficient power to fuel the engine and a significant increase in fuel consumption.
Lubricating oil – Piston rings also spread the lubricating oil as it moves up and down the cylinder liner thousands of times per minute. This makes the piston operate smoothly, reducing the risk of friction and scuffing between metal parts.
Heat regulator – During gas ignition, the temperature inside a piston can go up to 300 degrees Celsius. If this goes further, intense undistributed heat can damage the engine. Piston rings help regulate the temperature inside by releasing and transferring heat from the piston crown to the cylinder.
A barrier – A piston ring acts as a barrier between the piston and the cylinder wall, which prevents frictional force and eventually engine failure.

High-quality marine piston rings

Precision Products UK is a leading manufacturer and supplier of excellent quality marine piston rings to clients all over the world. We design and manufacture our own extensive range of piston rings to specifically meet the unique requirements of medium and large bore marine engines.

For more information about our marine piston rings, as well as other related products and services, please contact the Precision Products UK team by calling +44 1246 261621 or sending an email at

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Common Problems With Marine Engines

Common Problems With Marine Engines

To ensure that a marine engine will run efficiently at all times, a great deal of time, effort and resources must be invested, whilst also considering the complexity and number of parts it has. However, it is not uncommon to run into a few problems that can cause complications when taking the ship from one port to another.

To be better prepared and remedy these setbacks, we have compiled the most common problems you should be aware of when it comes to dealing with marine engines.

Air leakage

Because the air control is constantly in an open position when the engine is in use, leakages in this area are often overlooked. Perform an intentional blackout for all the machinery to be in the ‘stop’ position so that it will be easy to locate the hissing noise or the leakage. This problem can be resolved by simply tightening or replacing the affected pipes or joints.

Fuel leakage or fuel valve malfunction

If there is an anomaly with the fuel treatment or the fuel temperature is not properly maintained, it will lead to cracks and leakages in the fuel system, especially in the fuel valve. To avoid this from happening, the ‘high-pressure leak off tank’ level and alarm must be constantly supervised.

Sparks in the main engine exhaust

Due to the boats/ships constantly slow sailing and frequent manoeuvrings, sparks from the main engine’s exhaust may occur occasionally, which leaves soot deposits on the EGB boiler path. Schedule a monthly cleaning of the exhaust gas boiler to avoid this issue.

Stuck fuel rack

There may be times when there is an alteration in the engines RPM or the engine will not even start at all, especially with 2 stroke marine engines. This usually happens when the fuel rack gets stuck, resulting in a lack of fuel supply to the concerned unit. To prevent this from happening, ensure that the mechanical links are well lubricated and greased at all times.

Faulty alarms and sensors

The main engine is equipped with different sensors that measure and transmit actual data to the alarm console. However, these sensors may crash due to factors such as vibration, high temperature, humidity and dust. To avoid receiving false distress signals regularly check all engine room sensors and alarms.

Precision Products UK specialise in a comprehensive range of piston ring solutions for medium to large bore engines. Whether you have a new build, engine service or refurbishment demands, we’re sure to offer you the ideal solution. Click here or more information on how you can place an order.

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Understanding The Difference Between 2 Stroke and 4 Stroke Engines

Understanding The Difference Between 2 Stroke and 4 Stroke Engines

If engine design is of interest for you, then you may have already heard of the two main types of internal powered combustion engines which are the 2 stroke and 4 stroke engines. The term ‘stroke’ refers to the movement or cycle of the piston in the engine. For you to better understand the functions of these engines and choose the one that is most suitable for your business’ need, read on to know about the differences of each.

How The Engines Work

  • A 2 stroke engine has ports which make its design much simpler whilst a 4 stroke engine appears to have a complicated design due to its valve mechanism.
  • 4 stroke engines are comparatively heavier in contrast to 2 stroke engines.
  • The top side of the piston on a 4 stroke engine is flat whilst a bump or protuberance may be needed on the top side of a 2 stroke engine’s piston.
  • Whilst a 2 stroke engine becomes loud when operating, a 4 stroke engine makes less noise in comparison.
  • A 4 stroke engine completes 2 rotations of the crankshaft after finishing one cycle, where a 2 stroke engine completes only 1.
  • With a 4 stroke engine, power is produced once every 4 strokes of the piston whilst power is produced every 2 strokes in a 2 stroke engine.
  • Regular addition of oil is required for a 2 stroke engine, unlike a 4 stroke engine.
  • With a 2 stroke engine, the air-fuel mixture enters through the inlet port and travels to the combustion chamber, passing through the crankcase. The mixture on a 4 stroke engine, on the other hand, remains in the combustion chamber only.

A leading established brand for a significant number of 2 stroke and 4 stroke diesel engines, we, at Precision Products UK, continue to combine our key strengths of quality, speed and flexibility with our extensive range of materials and coatings. Our products are proudly manufactured here in the UK and are supplied worldwide. Give us a call on +44 1246 261621 to discuss your project with us today.

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A Guide To Piston And Ring Clearance in Marine Diesel Engines

A Guide To Piston And Ring Clearance in Marine Diesel Engines

Marine piston rings are an important part of the compression system in a 2 stroke or a 4 stroke engine. To ensure that the piston rings will perform thoroughly, it is important to know the required properties and types of piston rings used for specific purposes.


Compression piston rings for two stroke large engines seal the chamber to prevent high-temperature combustion gases from escaping whilst distributing the oil on the liner surface.


Apart from ensuring that the piston rings have a similar thermal expansion to that of the cylinder liner, listed below are some of the major mechanical properties of piston rings that maintain their optimum clearances:

  • Low Friction and Self Lubricating
  • Load Bearing
  • Corrosion Resistant
  • Good Heat Transfer
  • Innate Hardness for Wear Resistance


Ring clearances are essential to allow movements and thermal expansion. Here are two kinds of clearances you should know about:

  • Vertical Clearance

This clearance is important for free movement during operation and must be kept to a minimum to avoid ring hammering and ring groove wear. However, when the vertical clearance is insufficient, it may cause rings to stick in the groove or break as they come up to operating temperature.

  • Gap Clearance

Whilst gap clearance should never close completely, it must be as small as possible and should be maintained within a range of 0.4 – 0.5 per cent of a cylinder bore. The ring may break due to the restriction on its thermal expansion when coming up to working temperature if the ring gap is too small. Keep in mind that too small a gap may cause an increase in liner wear or lead to liner scuffing due to the oil film breaking down.

Based in Chesterfield, UK, Precision Products UK specialises in the design and production of piston rings and metallic seals that are all manufactured here in the UK. We supply expert products and services to customers from different industries worldwide. Click here to know how you can order or contact us via +44 1246 261621 for more information.

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Privacy Policy

At PPUK  we’re committed to protecting and respecting your privacy.

This Policy explains when and why we collect personal information about people who visit our website, how we use it, the conditions under which we may disclose it to others and how we keep it secure.

We may change this Policy from time to time so please check this page occasionally to ensure that you’re happy with any changes. By using our website, you’re agreeing to be bound by this Policy.

How do we collect information from you?

We obtain information about you when you use our website, for example, when you complete the contact form or engage with other forms within our site.

What type of information is collected from you?

The personal information we collect might include your name, address, email address, IP address, and information regarding what pages are accessed and when.

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We may use your information to:

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We review our retention periods for personal information on a regular basis. We are legally required to hold some types of information to fulfil our statutory obligations. We will hold your personal information on our systems for as long as is necessary for the relevant activity, or as long as is set out in any relevant contract you hold with us.

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We will not sell or rent your information to third parties.

We will not share your information with third parties for marketing purposes.

Third Party Service Providers working on our behalf: We may pass your information to our third party service providers, agents subcontractors and other associated organisations for the purposes of completing tasks and providing services to you on our behalf (for example to process donations and send you mailings).

However, when we use third party service providers, we disclose only the personal information that is necessary to deliver the service and we have a contract in place that requires them to keep your information secure and not to use it for their own direct marketing purposes. Please be reassured that we will not release your information to third parties beyond the company for them to use for their own direct marketing purposes, unless you have requested us to do so, or we are required to do so by law, for example, by a court order or for the purposes of prevention of fraud or other crime.

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You have a choice about whether or not you wish to receive information from us. If you do not want to receive direct marketing communications from us about our exciting products and services, then you can select your choices by ticking the relevant boxes situated on the form on which we collect your information.

We will not contact you for marketing purposes by email, phone or text message unless you have given your prior consent. We will not contact you for marketing purposes by post if you have indicated that you do not wish to be contacted.

[You can change your marketing preferences at any time by completing the opt out form here: or by contacting us by email at or by writing to Precision Products Ltd,Unit 1, Cobnar Wood Close, Chesterfield Trading Estate, Chesterfield, S41 9RQ, England. Alternatively, you can telephone+44 1246 261621.

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The accuracy of your information is important to us. You have the right to request a copy of the information we hold about you so that you can ensure its accuracy. You can do this by the following methods:

Send an email to the administrator here and request the information held about you or by writing to Precision Products Ltd,Unit 1, Cobnar Wood Close, Chesterfield Trading Estate, Chesterfield, S41 9RQ, England. Alternatively, you can telephone+44 1246 261621.

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Visitors / users of the site should have the ability to have all records of their personal data held by a business where there is no legitimate reason for that business to maintain that reason. This includes where GDPR is super-ceded by other laws governing the details obtained.

You can do this by the following methods:

Send an email to the administrator here and request the information held about you is erased or by writing to Precision Products Ltd,Unit 1, Cobnar Wood Close, Chesterfield Trading Estate, Chesterfield, S41 9RQ, England. Alternatively, you can telephone+44 1246 261621.


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When you give us personal information, we take steps to ensure that it’s treated securely. Any sensitive information (such as credit or debit card details) is encrypted and protected with the following software 128 Bit encryption on SSL. When you are on a secure page, a lock icon will appear on the bottom of web browsers such as Microsoft Internet Explorer.

Non-sensitive details (your email address etc.) are transmitted normally over the Internet, and this can never be guaranteed to be 100% secure. As a result, while we strive to protect your personal information, we cannot guarantee the security of any information you transmit to us, and you do so at your own risk. Once we receive your information, we make our best effort to ensure its security on our systems. Where we have given (or where you have chosen) a password which enables you to access certain parts of our websites, you are responsible for keeping this password confidential. We ask you not to share your password with anyone.


Links to other websites

Our website may contain links to other websites run by other organisations. This privacy policy applies only to our website‚ so we encourage you to read the privacy statements on the other websites you visit. We cannot be responsible for the privacy policies and practices of other sites even if you access them using links from our website.

In addition, if you linked to our website from a third party site, we cannot be responsible for the privacy policies and practices of the owners and operators of that third party site and recommend that you check the policy of that third party site.

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Transferring your information outside of Europe

As part of the services offered to you through this website, the information which you provide to us may be transferred to countries outside the European Union (“EU”). By way of example, this may happen if any of our servers are from time to time located in a country outside of the EU. These countries may not have similar data protection laws to the UK. By submitting your personal data, you’re agreeing to this transfer, storing or processing. If we transfer your information outside of the EU in this way, we will take steps to ensure that appropriate security measures are taken with the aim of ensuring that your privacy rights continue to be protected as outlined in this Policy.

If you use our services while you are outside the EU, your information may be transferred outside the EU in order to provide you with those services.

Review of this Policy

We keep this Policy under regular review. This Policy was last updated in May 2018.

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