how does a hydraulic cylinder work

Seals are essential to fluid power engineering, as they prevent a fluid or gas from passing between the different components of a hydraulic cylinder. Dynamic (used when parts are in motion) or static (fixed application), different types of seals, each have their own role to play, in ensuring a cylinder runs as smoothly as possible. Our quick guide below shows the main types of seals that you would find in a cylinder and describes how they operate. <h4>Wiper Seals </h4> <a href="https://www.fpeseals.com/seals/wiper-seals">Wiper seals</a> or Scraper seals are designed in a way to keep external contaminants out of a hydraulic system, by cleaning the rod in the cylinder on each cycle. <h4>Rod Seals </h4> Also known as <a href="https://www.fpeseals.com/seals/rod-seals">Gland seals</a>, Headbush or Neck Seals, Rod seals act as a pressure barrier to maintain and regulate the operating fluid in a cylinder. They can seal the pressure from one side (single-acting) or from both sides (double-acting). Rod seals are key in preventing corrosion. <h4>Static Seals </h4> These are used to create a seal between fixed components. The full range of <a href="https://www.fpeseals.com/seals/static-seals-o-rings">static seals</a> include o-rings, back-up rings, flange seals, bonded washers and OP seals. <h4>Piston Seals </h4> <a href="https://www.fpeseals.com/seals/piston-seals">Piston seals</a> are important for controlling the motion of a cylinder. It creates a barrier for dynamic pressure between the piston and the cylinder, preventing fluid from passing the piston and allowing the cylinder to extend and retract. <h4>Guide Rings</h4> <a href="https://www.fpeseals.com/seals/bearing-rings/guide-rings">Guide rings</a> also known as bearing rings, stop metal-to-metal contact between two dynamic cylinder components. This is crucial in the prevention of damage to the two moving surfaces. <h3>The right seal for the job</h3> When selecting the best seals for your hydraulic ram, both at OEM or repair stage, it’s important to consider the parameters of the application and the operating conditions. High pressure, medium used, extreme temperatures, aggressive chemicals, working environment and legislation standards will all have an impact on the chosen material of seal. Over time however, it is expected that hydraulic seals will eventually need replacing, this can be down to general wear and tear, improper installation or exposure to extreme elements. Most replacement seals, for most applications can be found off the shelf and seal kits for well known applications can be picked up easily. If you require any further advice regarding seals and their applications, the team of experts at FPE Seals can help you source what you need. Can’t find what you’re looking for? We can also custom-manufacture a full range of seals, in a full range of materials to meet your exact requirements. <a href="https://www.fpeseals.com/contact" class="button medium">Contact Us</a>

Seal Failure: Common Causes and Cures

In the world of machinery, repair and maintenance is a simple fact of life. So, it should come as no surprise that when it comes to sealing products being used for hydraulic and pneumatic applications, wear and tear is inevitable Even when you have diligently installed the most robust product, in the best kind of material, certain factors will always lead to seals eventually having to be replaced. Thankfully in most cases, problems can be identified early, before any serious operational damage can occur, and seals are easily reinstated. Here we take a look at typical seal failure, the likely causes, and what can be done to rectify the problem. Hardening Hardening of the dynamic face has caused glazing and cracks. Cause: Heat generated by high speed. Cure: Slow stoke speed or use an alternative seal device. The whole seal has gone hard and elasticity is lost. Cause: High fluid temperature, deterioration of fluid or problem with the compatibility of the seal to the fluid. Cure: Lower the oil temperature, renew fluid or change to a different seal compound. Wear The dynamic face of the seal is worn to a glossy mirror-like finish. Cause: Insufficient lubrication Cure: Check oil viscosity or use an alternative seal device. Wear on dynamic lip of seal is egg-shaped. Cause: Rod or piston bore is not concentric Cure: Hone to within seal specifications or replace the worn rod or cylinder tube. Signs of abnormal wear on one side of the dynamic lip. Cause: Worn bearing or wear ring. Excessive lateral load. Cure: Replace bearings. Increase bearing area. Scarring Cut or dent on the lip. Cause: Storage on a nail or peg. Improper installation tool Cure: Store flat in a plastic bag in a closed cardboard box. Installation tools should not have sharp edges. Scratched on the dynamic side. Cause: Scars on the rod or bore or foreign material in fluid Cure: Hone, polish and deburr metal parts or flush the system. Swelling Material is soft and misshaped. Cause: Absorption of fluid. Fluid and seal are incompatible or the there is water in the system. Cure: Change the seal compound or system fluid. Or flush the system. Deterioration Cracks and loss of elasticity. The material easily crumbles. Cause: High fluid temperature. Exposure to ozone or sunlight. Cure: Lower oil temperature. Store seals away from sunlight and arc welding area. Grooving Axial cuts on the dynamic side. Cause: Metal chips or other foreign material in system. Imploding air bubbles. Cure: Flush System. Bleed air from the system. Extrusion Extruded material on the dynamic side of heel Cause: Gap between mating surfaces is too wide, worn bearings or extreme pressure. Cure: Employ a back ring, replace the bearings or use an alternative seal. Extruded material on the static side of the seal. Cause: Uneven support surface or undersized back-up ring. Cure: Machine surface. Correct back up size. Fracturing Chunks of material torn from the dynamic side. Cause: Excessive back pressure. Cure: Check relief valves. Pressure side of seal burned and broken. Cause: Explosion of residual air at high pressure. ‘Dieseling’ Cure: Bleed air from the system. Long cracks in the “V” portion of the seal. Cause: Frequent high pressure shocks or spikes. Low temperature start-up. Cure: Use alternative style seal. Warm system before applying pressure. Breaking off of entire dynamic side. Cause: Deterioration of material and/or fluid. Cure: Use alternative material or seal. Flush system. Replacement seals and seals kits, for most applications can be found off the shelf and despatched to you quickly. If you require any further advice regarding seals and their application, the team of experts at FPE Seals can help you source what you need. Can’t find what you’re looking for? We can also custom-manufacture a full range of seals, in a full range of materials to meet your exact requirements. <a href="https://www.fpeseals.com/contact" class="button medium">Contact Us</a>

Rod Vee-Packing Seals

Rod T-Seals

Rod Composite Seals

U-Ring Rod Working Seals

Rubber & Fabric Rod Seals

D Rings

Washers

OP Seals

O Rings with Back Up Rings

Static Seals

Quad Rings

O Rings

Back Up Rings

Pneumatic Piston Seals

Pneumatic Guiding Wiper Seal

Pneumatic Wiper Seals

Pneumatic Cushion Seals

Pneumatic Complete Piston Seals

U-Ring Seals

Piston T-Seals

Split Piston Seals

Solid Piston Seals

Rubber & Fabric Piston Seals

Grooved Piston Seals

Cup Seals

Piston Composite Seals

Piston Rings

Hydraulic Complete Piston Seals

Piston Vee-Packing Seals

Guide Ring Wipers

Metal Cased Wipers

Flexible Wipers

Double Lipped Wipers

Wiper Composite Seals

Cushioning Rings

Retaining Rings

Guide Strip

Guide Rings

V-Seals

Rotary Seals

Oil Seals

Seal Kits by Manufacturer

MAXI Kits

Service Kits

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Caterpillar Locknuts

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Pick Sets

Tools

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Single Acting Cylinders

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Breathers

Cushioning Components

End Caps

Glands

Locking Nuts

Flanges

Tubes

Rods

Plugs

Pistons

Ports

Connection Tubes

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Radial Ball Joints

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Fork Ends

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Clamps

Gauges

Lubrication

Locking

Pins

Trailer Brake Rams

Spanners

Hand Pumps

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Couplings

Overcentre Valves

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Check Valves

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Hose Protection

Protection Plugs

Protection Caps

Cylinders in Kit Form

Piston Seal Kits

Gland Seal Kits

DC-Other-ANSI

DC-Other-General Process

SC-Multispring-Other

SC-Multispring-API

SC-Multispring-General Process

SC-Multispring-ANSI

SC-Single Spring-ANSI

SC-Single Spring-General Process

SC-Bellows-Others

SC-Bellows-API

SC-Bellows-General Process

SC-Bellows-ANSI

SC-Other-Other

DC-Multispring-API

DC-Multispring-General Process

DC-Multispring-ANSI

DC-Bellows-API

DC-Bellows-ANSI

SPL-Multispring-General Process

Bellows

Simple Spring

Wave Spring

Multispring

BORNEMANN®

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APEC®

ALLWEILLER®

ALFA LAVAL® (CONTHERM®)

ALFA LAVAL®

AFEC®

ABS®

GORMAN-RUPP®

GRUNDFOS-SARLIN®

GRASSO®

FRISTAM®

FRICK®

FLYGT®

EMU®

EBARA®

CN-PUMPS®

CALPEDA®

JOHNSON®

JABSCO®

INBEAT®

IMO®

HOWDEN®

HISAKA®

HILGE®

HIDROSTAL®

HERBORNER®

KSB®

PUMPEX®

PEDROLLO®

NOCHI®

NIKUNI PUMPA®

MYCON®

MOUVEX®

MARELLI®

LOWARA®

SEDICAL®

TUCHENHAGEN®

TSURUMI®

SUNTEC®

SOMEFLU®

SALMSON®

SABROE®

WITT®

WILO®

WAUKESHA®

VIKING®

What is a Hydraulic Ram and How Does It Work?

A hydraulic ram is a cylinder with a movable rod that can move a mass, or an obstruction as so required.

In principle, a hydraulic cylinder ram works by an external fluid being pumped into either side of a cylinder simultaneously, this creates a high pressure and low-pressure side within the cylinder depending on the load that it is trying to move.

Here we explore some of your commonly asked questions surrounding hydraulic rams, what they’re used for, how hydraulic devices work, and how hydraulic rams work.

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How does a hydraulic device work?

Hydraulic devices use fluid that is moved by an external pump driven by a power unit. Hydraulic devices are designed around the principle that liquids are always considered to be incompressible. This means that when a force is applied at one point, the liquid will transfer an equal force at another point.

Most common hydraulic devices work by using a hydraulic pump, a reservoir for fluid storge to the pump. Mechanical energy is converted to hydraulic energy, moving the liquid through a system. Valves are used to regulate the flow of the liquid and control the pressure of the device. A hydraulic cylinder then converts the hydraulic energy back into mechanical energy.

There are a variety of hydraulic devices, including hydraulic rams, but most will use these components in their operation.

How do hydraulic rams work?

Hydraulic rams consist of several components:

• Cylinder
• Piston
• Neck Gland
• Rod
• Cylinder Ports
• End Caps

The area between the piston and the gland (rod side) is called the Annular side, & the area between the piston & the end cap is called the Full-Bore side.

Pumping fluid into the cylinder port on the Annular side of the cylinder will result in the rod being retracted, giving you a closed centre. Reverse the flow into the opposite port on the Full-Bore side and the piston will then extend the rod out of the cylinder (open centres), at the same time pushing the oil from the Annular side (low pressure) back to tank.

What is a hydraulic ram used for?

Today, hydraulic rams are used all over and have a variety of uses, from heavy plant and mining machinery such as excavators and diggers, agricultural equipment, to food & beverage and packaging machinery, deep sea, marine and automotive applications, to hand tools, fairground amusements and even zoo doors...the list goes on and on.

FPE Seals is a manufacturer and distributor of hydraulic cylinder parts and seal kits for devices including hydraulic rams. Shop online or contact us and find out how our cylinder parts can help improve your hydraulic systems.