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Parker 689B series valve obsoleted

Parker 689B series valve

Parker 689B series valve

So, Parker continues to discontinue nice products 🙂

Now they obsoleted valves 689B series…

It is hard to find panel-mounted hydraulic push button valves. Most of the push-button valves are cartridges and to be assembled with a body. Body has mounting holes and some design of brackets is required to mount to assy body + cartridge to the panel.

The benefit of the valve 689B series was in mounting holes at the top, which lets easy mount to the panel.

In most applications, I easily replaced this type with an electrical button that operates a simple solenoids valve. But some specific applications require simple hydraulic manual control (some equipment at the rig, where the electrical-over-hydraulic control is not allowed by safety reasons.)

So, the question to you guys, can you advise an elegant replacement for this valve?

Updates:

Jan 29, 2020 By the advice of couple vendors I ‘m going to try to use Doering push-button valve as a replacement:

Doering push button valve

Doering push-button valve

Different spacers can be used, but I’m going to proceed with custom spacers to make button hight as low as possible over the panel. Not really elegant solution but time is limited and I need to make a decision. I will update this pose as soon as the panel is done to show how the solution looks like.

Rexroth A4VG clones

Just in case if you need replacement for Rexroth A4VG, it seems to me these guys are brothers:

Rexroth A4VG Parker C-series Dana Brevini S6CV
Rexroth A4VG Parker C-series Dana Brevini S6CV
Available Displacements:
28cc, 40cc, 56cc, 71cc, 90cc, 125cc 55cc, 81cc, 136cc 75cc, 128cc
Nominal pressure:
400 bar (5800 psi) 420 bar (6090 psi) 400 bar (5800 psi)
Maximum Permissible Fluid Cleanliness:
20/18/15 20/18/15 20/18/15
Operating temperature:
−25..+110 °C -25..90 °C -25..90 °C
Viscosity range at operating temperature:
16..36 cSt 15..40 cSt 15..40 cSt
Available control systems:
HD” Proportional control, hydraulic C” Hydraulic proportional control with internal feedback HIR” Hydraulic proportional with feed-back
EP” Proportional control, electric F” Electric proportional with internal feedback HER” Electric proportional with feed-back
ET” Electric control, direct operated, two pressure reducing valves G” Electric proportional without internal feedback HEN” Electric proportional without feed-back
EZ” Two-point control, electric E” Electric non proportional HE2” Electric on-off
DG” Hydraulic control, direct operated D” Hydraulic proportional control without internal feedback HIN” Hydraulic proportional without feed-back
– – – A” Manual lever HLR” Manual lever with feed-back

Semi-closed hydraulic circuits

Have you ever heard about the semi-closed hydraulic circuit?

The idea is to use open loop pumps in closed loop circuit. In the latest eighties, Mannesmann Rexroth (yes, that time Mannesmann yet!) even offered pumps A4VSH, especially designed for semi-closed circuits.

Bosch Rexroth A4VSH pump

Bosch Rexroth A4VSH pump, from catalog RE92110/01.89

The main difference between closed loop pumps and semi-closed loop pumps was in addition block mounted to the ports A and B with check valves which let to supply suction flow from the tank, while mainstream comes from the motor to pump’s suction port:

Since that time Rexroth still builds A4VSH, but there are a limited number of sizes and options available and its no longer a mainstream published option.

But to make a semi-closed loop you do not need some special pump, it’s really easy to turn most standard open loop pump into a semi-closed loop circuit. Of course, you have to have some knowledge about the application and actuators before trying to apply it. If the pump does not have an integrated boost pump and check valves these are commonly added via an external gear pump and external check valves.

Here is the simplest example of the semi-closed circuit schematic where a regular open loop pump with LS control is involved to run two motors with independent proportional control of their speeds:

Parker Gold Cap pumps Interactive Tool

Parker Gold Cap pumps interactive tool

Parker Gold Cap Pumps Interactive Tool

Just have been gotten an interesting link from Parker distributor for their Gold Cap Pumps interactive online software:
https://divapps.parker.com/divapps/hpps/gold-cup-pump/

Here you can:

  • take a look at how different valves work internally in the pump;
  • check schematic for each pump’s option and size;
  • learn the terminology of pump internal components;
  • watch the video and download PowerPoint presentation about these pumps;
  • at the bottom of this software, you can find a link to the eConfigurator.

My notes:

  • Gold Cap pumps are pretty complicated, so any additional info like this is always helpful.
  • It will be awesome if the pumps schematics can be downloaded in DXF format to integrate into my projects.