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Hydraulic Elevator Modernization

Elevator upgrades can ensure proper mechanical operation that is essential for safe operations and for you to fully realize the benefits associated with any modernization program. Hydraulic elevators operate at slower speeds and are commonly found in locations which serve up to 79′-0″ of travel. The following components must be considered when determining modernization recommendations for Hydraulic elevators:
  • Jack Assembly
  • Control Valve
  • Overspeed/Pipe Rupture Valve
  • Silencer
  • Car Sling/Platform
  • Guide Shoes
  • Buffers



A power unit is used on all hydraulic elevator equipment types. A standard power unit consists of a tank, pump, motor, control valve, and silencer. The power unit pumps oil to push the piston up. It also allows the oil to return to the tank as the car travels down

Jack Assembly


A conventional jack assembly is one installed in the ground. Major components of a conventional jack assembly include the cylinder, plunger, jack head, packing and flange, casings, and protection (if any). When considering a modernization we will assess the age, condition and operation of jack assembly components to determine if upgrade or replacement are recommended.

Recent Code changes in several area States have required or recommend replacement of Jack assemblies installed prior to 1972.

Control Valve


Control-ValveThe Control Valve is the device on hydraulic elevators which controls the oil flow to and from the jack. Hydraulic elevators only perform as well as the valve. If the flow of oil from the power unit to the jack is erratic, the performance of your elevator will be as well, causing your elevator to ride rough, bouncy, noisy and/or to level improperly. There are many makes and models of valves all of which have fine adjustment pins, filtering screens and “O” rings prone to wear and tear. Many older style valve components are hard to get or obsolete. A poorly maintained or adjusted valve is one of the most common causes of erratic operation on hydraulic elevators.

We will assess the condition of your valves and determine if a rebuild, upgrade or replacement is necessary.
We commonly recommend ThyssenKrupp Elevator’s patented I-Series® valve. The industry’s number one selling valve, the pistons in the I-2® and I-3® valves are machined to reduce friction, making the operation of the elevator smoother, quieter and more consistent. In need of ThyssenKrupp elevator repair? Our team can help.

Overspeed/Pipe Rupture Valve



Many older elevators are not equipped with an Over speed Valve (OSV), ( also referred to as Pipe Rupture Valve). It is designed and can be adjusted in the field to stop the elevator in the event of an over speed condition caused by a broken supply line or an abnormally high rate of oil flow between the OSV and the power unit. The OSV will not stop the car from over speeding due to underground cylinder leaks and is not a substitute for cylinder replacement or other safety devices. We do recommend one be installed if it does not already exist.



A muffler type device installed in the oil line of a hydraulic elevator pump is designed to reduce noise produced as oil moves through the line. These units can develop leaks and lose their effectiveness. We can assess your silencer for proper performance and determine if replacement is in order.

Car Sling/Platform


The Sling is the basic frame which consists of two stiles, a crosshead and a bolster or safety plank which supports the platform and cab of an elevator. The platform or floor of the elevator is placed in the sling and supported by brace rods in each corner.

The Crosshead is the upper member of the car frame. The Stiles are the vertical member of the car sling, one on each side, that fasten the crosshead to the safety plank. The Brace Rod is a rod extending from the elevator platform framing to another part of the elevator car frame or sling for the purpose of supporting the platform or holding it securely in position. Brace rods are supports for the outer corners of the platform, each of which tie to upper portions of the stile.

The Platform Isolation is Rubber or other vibration absorbing material which reduces the transmission of vibration and noise to the platform. These pads are often replaced when modernizing as new isolation is more resilient and helps to reduce vibration and improve the comfort of the ride for passengers.
The Bolster is the bottom horizontal member of a hydraulic car sling, to which the platen plate attaches. The Safety Plank is the bottom member of a sling for a traction elevator which contains the safety.

Guide Shoes


Guide shoes are devices mounted on the top and bottom of the elevator sling which slide or roll on the rails to guide the elevator through the hoistway. They are equipped with rollers, liners and tension springs which are subject to wear and tear. Some older style guide shoes require a poured lead babbitt shoe, rather then a replacement nylon or neoprene liner.
If guides are not maintained or adjusted properly your elevator will tend to rock, sway, squeak or even rumble its way through the hoistway. We will assess you guides type and condition and recommend repair or replacement as required.



A Buffer is a device designed to stop a descending car or counterweight beyond its normal limit and to soften the force with which the elevator runs into the pit during an emergency.

A spring buffer is one type of buffer most commonly found on hydraulic elevators or used for elevators with speeds less than 200 feet per minute. These devices are used to cushion the elevator and are most always located in the elevator pit.
An oil buffer is another type of buffer more commonly found on traction elevators with speeds higher than 200 feet per minute. This type of buffer uses a combination of oil and springs to cushion a descending car or counterweight and are most commonly located in the elevator pit. Because of their location in the pit buffers have a tendency to be exposed to water and flooding. They require routine cleaning and painting to assure they maintain their proper performance specifications. Oil buffers also need their oil checked and changed if exposed to flooding.

When planning a modernization we will assess the type and condition of your buffers and recommend if repair or elevator replacement parts are required.