FAQ

Pump / Motor Rotation Direction

For standard pumps the direction of rotation is clockwise when looking at the shaft of the pump or when looking at the fan side of the motor coupled to the pump.

Updated VMDC Relief Valve

The VMDC relief valve has been updated. The new version is backward compatible but pressure ranges have changed on the options slightly. Refer to the attached PDF for details on the new VMDC relief valve. Additionally, please note that installation torque has changed. The old VMDC had a tightening torque of 40 Nm. The new version has a tightening torque of 30 Nm.

Specifications: VMDC Specifications

Q-Series Square Plastic Tanks – Mounting

The new Q Series plastic tanks require (4) clamping brackets part number E60513022 to mount:

Hydronit Q Series Square Plastic Tanks

E60513022 Clamping Brackets

When ordering part number TCTAH00002 or TCTAH00005 as a spare part the following components are included:

(1) Tank
(1) Clamp Band
(1) Filler Breather Cap
(4) Clamping Brackets

Note: The tanks are mounted with (4) TEM6X14 Hex Head Screw with integrated washer (Class 8.8). These screws are not included when the tank is ordered as a spare part but may be purchased separately.

What is the difference in a G plug (E70100005) and a XP plug (E70200010) and can they interchange?

The G plug (E70100005) and a XP plug (E70200010) look very similar but they are not interchangeable. Physically they will both seat in each cavity but the seals are designed differently to create proper sealing in the direction that the high pressure fluid interacts with the seals.

The XP Plug is designed specifically for Cavity 1 where a relief valve is traditionally used. It is used to seal that cavity when a relief valve is not in the system where pressurized oil pushes against the end of the cartridge.

The G Plug is designed to be used in cavities where pressurized oil passes across the middle of the cartridge.

You can identify the XP plug vs. the G plug by the orientation of the seals on the plug. See the images below for details noting the position of the seals on the end of the cartridge:

XP Plug – E70100010 Side Profile

G Plug – E70100005 Side Profile

Can I use PPC Modular Blocks on a smaller PPM power unit?

PPC modular manifold blocks can be used on PPM power units. To do so you need to add a M60403008E PPM to PPC Adapter plate to the manifold stack. See the image below for an example.

PPM to PPC Adapter Catalog Page

PPM to PPC Adaptor M60403008E Example

How do I connect my Hydronit DC Motor driven power unit?

Some example connection schemes are shown below:

DC Connection Scheme

At what temperature does the thermal protection activate on M46 DC Motors?

The thermal protection switches when the motor case reaches 110°C – 120°C (230°F – 248°F).

Is the central manifold available as a loose component?

Yes. We can supply either fully assembled and tested power packs or kits of loose components which can be kept in stock by our worldwide distributors and easily assembled to satisfy local market demand quickly and effectively. Central manifolds and other components are 100% tested even when supplied as loose parts.

Do I need special tools to assemble the components within the central manifold?

No. All the valves are screw-in type in a single-piece construction (no loose nuts, washers, or springs; nothing difficult to assemble or fall apart). The components can be easily assembled with simple hand tools and hexagon or Allen wrenches.

Which universal central manifold execution should I choose?

UA type is the most widely applied for single-acting or double-acting circuits. UB is the real Universal central manifold since, in addition to UA-type features, there are two extra lateral cavities to mount, for example, an integrated emergency hand pump and an externally adjustable flow control can be integrated in a UB manifold. U4 is recommended for compact and cost-effective double-acting circuits with a single cylinder, while UR is for bidirectional pumps.

Can I start single phase AC motors under load?

Single-phase motors have a reduced starting torque due to their intrinsic design. Starting torque is around 30-40% of the nominal torque at full power output. When designing circuits where a single-phase motor must start under load, a proper calculation must be done followed by a field test to ensure proper starting. Alternatively, you can overcome the problem with the startup valve SUV.

The SUV Valve can be optionally installed in our central manifolds. The valve is to be mounted in cavity 9 of U type and cavity 13 of S type central manifold. This cavity is not machined by default but is easily machined with a drill press by drilling cavity 9 and threading it for 1/4 BSPT. The function of this valve is to discharge the pressure inside the central manifold line between the pump and the check valve when the power pack is off. It is typically used with a single-phase motor starting under load, overcoming the inherent low torque at the start-up of single-phase AC induction motors

Are there special requirements to mount IEC B14 or NEMA motors?

No special tools are required. Please carefully follow the motor side coupling mounting dimension tolerance as per the relevant drawings. Failure to do so may cause malfunction of the power pack and even breakage of the coupling and pump.

What hydraulic fluids are compatible?

Use fluids rated for hydraulic use, mineral-based or synthetic ISO 6743/4 / DIN 51519, viscosity 15 – 100 mm2/s ISO 3448 (recommended viscosity 22 – 46 mm2/s)

Is orientation critical?

Most power units are designed for either vertical or horizontal installation. This is due to the fact that the suction filter and return pipes must be oriented correctly for the installation. The suction filter, suction pipe, and return lines can be purchased separately if you need to change the orientation of an existing unit.

What are the instructions for commissioning a unit?

After connecting the electric motor and the suction pipe, check the direction of rotation of the pump with pulses of 1÷2 sec. For standard pumps, the direction of motor rotation must be clockwise as viewed from the side of the motor fan.
Flush the oil at atmospheric pressure in order to remove any impurities and air bubbles from the circuit.
Connect all devices to the system and gradually increase oil pressure.
Check the oil level and, if necessary, fill up to the maximum level.
To ensure a correct and long-lasting operation, check the oil after 100h from commissioning and replace it every year or 300h of use whichever comes sooner.

For full instructions see:

Hydronit Instructions For Installation and Use

What are the recommended torques for fasteners and components?

The following table details the recommended torque values for fasteners and components in a Hydronit system:

General

M5: 4-5.5 Nm (35-49 lbf·in )
M6: 8-10 Nm (71-89 lbf·in)
M8: 16-20 Nm (142-177 lbf·in)
M10: 30-40 Nm (266-354 lbf·in)
3/8-16 UNC: 30-40 Nm (266-354 lbf·in)
5/16-24 UNF: 16-20 Nm (142-177 lbf·in)

Pumps

M5 for pumps gr.0.5: 8-9.5 Nm (71-84 lbf·in)
M8 for pumps «G» and «K» type gr.1: 21-25 Nm (186-221 lbf·in)
M8 for pumps «H» type gr. 1: 31-35 Nm (274-310 lbf·in)

Relays

Relay’s electric poles 5/16-24 UNF: 5 Nm (44 lbf·in)

Tanks

M5 for plastic tank: 0.3-0.4 Nm (2.66-3.54 lbf·in)
Metal tank’s plugs 1/2 BSP (ISO 228): Max 10 Nm (89 lbf·in)
Plastic tank’s plugs 1/2 BSP (ISO228): Max 10 Nm (89 lbf·in)
Steel clamp band for plastic tank neck: 2.1-2.5 Nm (18.59- 22.13 lbf·in)

Valves and Plugs

Valves and plugs 1/8 BSP: 12-15 Nm (106-133 lbf·in)
Valves and plugs 1/4 BSP (ISO 228): 15-20 Nm (133-177 lbf·in)
Valves and plugs 3/4-16 UNF: 25-30 Nm (221-266 lbf·in)
Valves and plugs M18x1.5: 30-35 Nm (266-310 lbf·in)
Relief valves M20x1.5: 50 Nm (443 lbf·in)
Relief valves M14x1: 15-25 Nm (133-221 lbf·in)
Valves and plugs 9/16-18 UNF: 6-20 Nm (53-177 lbf·in)
Valves and plugs 5/8-18 UNF: 15-25 Nm (133-177 lbf·in)
Valves 7/8-14 UNF: 45-55 Nm (398-487 lbf·in)

E10103010 EBP Flange

M6 for E10103010 flanges: 6 Nm (53.1 lbf·in)

General

Pumps

Relays

E10103010 EBP Flange

Recent Posts