How to assemble a SV or Series 20 Prince Manufacturing Corporation Stack Valve

Please visit Prince Manufacturing Corporations YouTube Channel to view the video of these guidelines.

Click HERE to see our SV (12 gpm) and Series 20 (20 gpm) Stack Valve features.  

SV Parts Manuals and Catalog pages to see both manual and solenoid operated.

Series 20 Parts Manuals and Catalog pages to see both manual and solenoid operated.

Make sure the environment is clean.  Avoid areas near grinding or even dusty areas.

Use a clean table that is free of dust and debris.  The tools should be clean.

Leave the parts and sections in their plastic bags until you are ready for them.

Gather and organize the parts needed for the assembly.

This will include:

                An inlet and an outlet casting

   

            The work sections.  There can be up to 10 of these per valve bank

The handle kit  (one handle per work section)

           The tie rods kit

           And the o-rings.

Inspect the ground mating surfaces making sure they are free of burrs or outward protrusions.

They must be free of scratches or dings in the mating areas of the o-rings.

You’ll notice a light film of hydraulic oil on these sections.  It remains on the sections because each valve is tested in our quality control program.  That film keeps the metal in ideal condition during shipping and should remain during assembly.

Lay the sections down, grooves up.

Put the o-rings in place after dipping each one in the hydraulic fluid that resides in these plastic bags.  This gives them a light oil film of lubrication.

Pinched o-rings will cause leakage so make sure they are fully seated.  There are typically 4 o-rings for each grooved section; for the SV family the larger o-ring goes in the round center groove and one of the smaller rings is re-oriented to fit in the “race track” groove.  The Series 20 family has orings of uniform size.  There may be extra orings in the kits you receive.

Thread nuts on one end of the tie rods, leaving approximately a quarter inch of threads extending from the nut and place lock washers inside the nuts.

Insert the tie rods through the inlet casting holes or the outlet casting holes…

depending on if you are assembling a Series 20 valve or an SV model, then place that cover section on the table like this…

with the o-rings facing up.  The grooves are on the Inlet Side of the Series 20 sections and on the downstream side of the SV family.

Repeat the o-ring steps for one work section at a time.  Do not use grease or any lubricant other than the hydraulic oil as that could cause leaking.

Lift the work sections and place them over the tie rods, making sure the o-rings face up and make contact with a flat surface, avoiding o-ring to o-ring contact.

After all work sections have been added, slide the inlet or the outlet section over the tie rods with the threaded ports facing up.

Place lock washers on the tie rods, then lightly snug up the nuts by hand.

Rotate the assembly to a horizontal position.  In order to keep it level, place a spacer block under the front edge of the inlet casting.  Using a torque wrench on one end and a socket wrench on the other, lightly tighten all three tie rods to about two-thirds torque.

Now you’re ready to progressively tighten the tie rod nuts to 12 and a half foot pounds of torque on the 3^rd and final pass. (The Series 20 family of valves is tightened  to 30 – 32 ft.-lbs.)

The handle assembly merely requires aligning the holes…and inserting the bolts and a cotter key. 

Use the handles or a handle fixture to shift all spools fully in and out…making sure there is no binding.

If a spool binds or for spring-center operators, does not return to center with spring force, loosen the nuts to about 1/3 torque and re-torque progressively in two passes.  If it still binds you probably have a pinched o-ring or contamination between sections.

Sectional valves from Prince Manufacturing Corporation…delivering to your bottom line through standard products and customized solutions.  Be sure to visit our website www.princehyd.com

Syncing Series Cylinders

          A condition that can be experienced with a set of Series Cylinders (Master and Slave(s)) is hydraulic cylinder creep, drift or movement when the hydraulic cylinder is not in use.  There can also be a condition that Series Cylinders will become out of sync, or not extend and retract at the same rate.  Below is a brief over view of some of the possible conditions that contribute to cylinder creep, drift or the series cylinder getting out of sync.  Keep in mind that the cylinders are only part of the hydraulic circuit and there can be other contributing causes.

Cylinder rod measurement:

Cylinder by-pass is a common field issue in Series Cylinder Systems, and a system review is required to determine the problem.

-Extend cylinders to the re-phasing position and lower hydraulics approximately 2".

-Then immediately disconnect the hydraulics from the tractor.

-Measure the length of the extended cylinder rod on each cylinder.

-Leave implement to stand for some time, i.e. 3 hours.

-Re-measure length of rods again and compare before and after measurements.

Please note: Variation can be expected if implement is left over a period of time where the temperature change affects the hydraulics by contraction or expansion.  Warm to cooler temperatures will cause the series cylinders to move.  Make sure measurements are taken at similar temperatures.

-When the 'suspect' cylinder has been identified, it is important that dis-assembly is carried out in a clean environment. The scoring of barrels and piston seals will usually indicate contamination of some type has entered the system.

Air in the system:

If one or all of the cylinders drift down or the system is 'spongy' air is likely present. Check for air bubbles going back to tank or by removing the return line and catching oil in a clean container. With the rod clevises disconnected and the cylinders vertical, hold in the re-phasing position until no aerated oil flows. Hydraulic oil flow should be kept to a minimum minimize heat while purging the air from the system.

Please note: Check the reservoir levels when carrying out this exercise. Once the air has been pushed out of the system the reservoir can become low.  This can introduce air in to the system again.

Miss-staged series cylinders:

Over a period of time the series cylinders may become miss-staged due to seal by-pass or differences between the rod side of the master cylinder and the extend side of the slave cylinder(s). To restage the cylinders it is necessary to extend them to the re-phasing position of for 30 seconds to 1 minute. Retract and then extend the cylinders to ensure that they are working evenly and staged with each other.  It may be necessary to repeat this process.

Below are a few scenarios where the main or master cylinder drifts in retract and how this retract drift could cause the slave cylinder(s) to extend or retract.

Keep in mind that Prince Manufacturing Corporation provides custom designs to fit specific applications.  Click here for details.

You may visit www.princehyd.com to view Prince Manufacturing Corporations standard Series Cylinders for further details.  Our Series Cylinder parts manuals can be accessed by clicking here.

LS-3000-1 Log Splitter Pressure Release Detent Question

     Question: On the LS-3000-1, what is the preset PSI and what is it adjustable to on the pressure release detent for the cylinder return?

     Answer: The LS-3000-1 pressure release detent is set to center the handle when the B port reaches a preset 1400 psi.  The inlet relief of the LS-3000-1 log splitter valve is preset at 2250psi @ 3 gpms and 105 degree F.  We recommend 250psi at a minimum between the inlet relief and pressure relief.  You would want your inlet to be 250psi higher than your pressure relief detent.

Below is the engineering spec section for for reference:

     Relief Valve Settings

          Unless otherwise noted with order code or on print, relief valve setting is to be 2250 psi* ± 100 psi @3 GPM ± 1 GPM.  All other settings to have similar ranges unless otherwise noted on assembly drawing or bill of material.

          *The Relief Pressure is defined as the pressure drop from the inlet of valve to the outlet of valve.  3 GPM must be flowing across the relief at 2250 psi.

     
     Detent release pressure to be 1400 psi ± 150 psi at 3 GPM as standard setting.  If the relief setting is less than 1650 psi, the detent release pressure is to be set at the relief setting at minimum minus 250 psi.

Be sure to check out our youtube videos also.

Please visit our LS-3000-1 Catalog pages.

Please visit our LS-3000-1 Parts Manual pages.

Please visit our LS-3000-1 Instruction Sheet pages.

Please visit our LS-3000-1 Availability.

Hydraulic Power Beyond

This is a really good video done by someone with
a Kubota Loader.  Very nice.  Below are some links to the RD5000 2 spool valve
that he is installing.

http://www.princehyd.com/Portals/0/valves/RD5000InstS.pdf

http://www.princehyd.com/Products/Product-Configurators/product/Valve/family/RD5200

http://www.princehyd.com/Portals/0/valves/RD5000Manual.pdf

http://www.princehyd.com/Portals/0/valves/ValvesRD5000.pdf

http://www.princehyd.com/Products/Hydraulic-Valves/Mono-Block/25-Gallon-Two-Spool

Genuine Replacement Seal Kits and Replacement Parts

       “Prince Manufacturing knows that you trust our products, processes and materials. 

       For this reason….. Do you risk the integrity, operations and potential safety of your equipment by NOT choosing to repair and/or refurbish Prince cylinders with genuine replacement parts from Prince?

       You are smart people…. You know you can’t tell by looking what kind of materials the major components of your cylinder are made from or the dimensions and tolerances for that matter.  The same goes for the seals that keep the oil where it belongs.   Prince Engineers make selections for the materials and geometry based upon your valued input for the form, fit and function of the products we made for you.

       After market replacement components made or supplied by someone else opens the door to unintended consequences….. ones that you may not have even considered.

       Trust Prince for your genuine replacement parts…..

              We designed them….

                     We manufactured them…

                           We stand behind them.  “

Please visit http://www.princehyd.com/Catalog/Parts-Manuals for our product part lists.

Regen Log Splitter - 20 GPM's?

The other day this question came in: Can I use the Prince LSR-3060-3 valve with a single stage 20 gpm pump?  The short answer is, No.

The longer answer is:

A regen circuit can be used to cause a cylinder to advance more rapidly than it could with pump oil flow only.  It can only be used to increase speed in the extension, not in the retract direction.

The basic idea of regen is to connect the rod end of a cylinder to its blind end or extend end, using suitable valving (see LVS, LVT and LVR Loader Valves and LSR Rapid Extend Log Splitter Valve), so the oil which normally would be returned to tank from the rod end will be combined with the pump oil.  This causes the cylinder to extend at an increased speed.  The hydraulic schematic on the bottom of the 2^nd page of this linked pdf shows the regen circuit with in the valve.

Some notes on Regen:

-       In regen, the force produced will be equal to that produced by the pump pressure based on the area of the rod.

-       Regn is usually used with cylinders that have large rods.

-       With larger rods, you need to be aware of pressure intensification.  Some applications require a relief valve on the retract port or rod end of the cylinder to handle the pressure intensification that can happen during extend.  Take for example the LSR-3060-3 Log SplitterValve.  It is going to provide extend flows up to 25 gpm with inlet flows of 4 gpm.  What would happen if you have an inlet flow of 20 gpm?  You would see extend flows attempt up to 120 gpm.  The work ports and hoses are the wrong size to handle 120 gpm.  You would see large pressure intensification.

-       Regen is typically used to get a machine or part of a machine (loader bucket tip, log splitter cylinder) into position or the force needed to perform the work is small.

-       Caution should be exercised when sizing the oil reservoir.  A cylinder with a larger rod will cause the oil in the reservoir to fluctuate more than normal.

So why does a regen circuit work?

            In a regen circuit the same amount of pressure is applied to both sides of the piston in the cylinder.  Working similar to a displacement style cylinder, the larger area (extend side) will cause the cylinder to move – extend.  The retract side or rod side doesn’t have as much area because the rod is taking up space – Force = PSI X sq inch area of rod.

I hope this is useful information for you. 

Prince Online Services - Shipment Tracking

Slow Loader - Spool Valve Problem

I received the following the other day: I purchased a two-spool control valve RD522GCGASA4B1 on 4/27/11 from xxxxxxxxx.  The unit is mounted on a '65 Ford 3400 with front end loader.  For the last 3 or 4 months the lift cylinders have been going up real slow at 1200 rpm.  If I increase the rpm's to 1800 it goes up a bit faster, but not much.  The lift cylinders are connected to the spool valve next to the relief valve.  The bucket cylinders snap bank and forth real fast with or without a load.  The normal load on the unit is a 900-1000 lb round hay ball.  

The other thing I noticed is that the spool valve for the lift cylinders will go to the bottom and hit a hard spot, then when forced with the handle will continue down and unload the lift cylinders allowing it to fall fast.  Is this normal?

I contacted your distributor they referred me to xxxxxxxx at your plant.

My questions are:  1 - What would cause this problem?   2 - If it is the spool valve can I fix it with new parts?  

These are typically easy issues to get thru depending on how much folks know about their system, sometimes they can get tricky.  The following are my comments:

The RD522GCGA5A4B1 doesn't change the flow rate or generate pressure (it does have a pressure relief cartridge at the inlet).  This valve takes the inlet flow and directs it to either the outlet, or one of the 4 work ports.  In the float position the inlet and work ports are connected to tank.  (http://www.princehyd.com/Products/Hydraulic-Valves/Mono-Block/25-Gallon-Three-Spool will provide details on this valve is a flow directing control valve.)

Cylinder speed or movement speed is determined by the amount of flow that is available.  With a gear style pump, increasing the pump speed or RPM’s will increase the flow rate or cause the cylinders to move faster.  The cylinder bore is another item that can affect cylinder speed.  A large bore cylinder (lets say 6 inch bore) being filled with 10 gpm’s will extend slower than a small bore cylinder (2 inch bore).  This has to do with area.  The 6 inch bore cylinder has more area to fill and is going to fill up slower than the smaller 2 inch bore cylinder.

You mention that shifting the handle in a certain position will cause the loader to fall fast.  This is likely the float option and based on your description, it is working fine.

Here is some information on trouble shooting a hydraulic system.  

Loader Valve Trouble Shooting maybe helpful also. 

Parts Manual for the RD5200 Valve.

With a pressure gauge these types of problems are usually easy to resolve.

Poor Gear Pump Flow

Please take the time to check out the hydraulic pumps listed at this Link . You will find some useful information.
Common Causes of Hydraulic Pump Failure
Q: What are the most common things apart from pressure or speed that can cause a pump to fail?
A: The most common things that cause a pump to fail fall into three categories; Cavitation, Contamination, and Heat.

• Cavitation: This is caused by a lack of oil flowing into the inlet port. It will damage the pump, and reduce flow. If you see foamy oil, it is a good indication of cavitation. Increasing the size of the inlet line or reducing flow can help with cavitation problems. Removing any elbows, bends, or filters on the inlet line can also help. Lastly, making sure that the oil reservoir is above the pump may also be beneficial.
• Contamination: Contamination will not only cause damage to the pump, but may also plug valves, reliefs, etc. in the system. It is important to have the proper filtration in the system, including changing filters regularly.
• Heat: Any Hydraulic system will generate heat. It is important to deal with that heat so that the oil temperature does not rise high enough to cause damage to seals, valves, etc. Having a properly sized oil reservoir (or oil cooler if necessary) is important in order to avoid excessive heat buildup in the system.

Lastly, make sure to refer to your manual for the proper pressure/speed limits. Exceeding those limits will damage a pump, and cause it to fail prematurely.