FAQ

On this page you will find the answers to the most frequently asked questions about our services and Vivoil hydraulic products.

Availability and delivery times 

Do you have ready-made products in stock?

No, because we only manufacture to order and delivery times vary based on workload.

What are the delivery times?

Delivery times vary based on workload and time of year.  Vivoil closes each year for 3 weeks in August and 2 weeks in December.
Orders arriving near August and at the turn of December and January will be handled taking into account these closing times.
Subscribers to our newsletter receive regular communication with exact opening and closing times. Are you interested in receiving these updates? Subscribe to our newsletter

Is it possible to anticipate the delivery?

At Vivoil we always try to give the best service to our customers. Contact our sales department that will evaluate if it is possible to anticipate your delivery.

Customizations

Can I contract you to manufacture special products from my own design or from the design of one of my customers?

Yes, of course. At Vivoil we are always available to evaluate specific requests and customizations, because our production is flexible. Contact us and we will verify the feasibility of your project.

General questions and information about the Vivoil product range

I have a hydraulic component produced by another company and I want to replace it with a Vivoil product. Which code can I use?

Contact our technical department, we will help you find the Vivoil component that matches the one you have.

I bought a Vivoil product several years ago and I want to replace it starting from the code stamped on the component: is it possible?

In 2010 we changed our product marking system. Years ago we used laser engraved marking, then we switched to the bar code label, which is much more complete, because thanks to the unique code we can trace exactly every single component made and sold.
Therefore, if your Vivoil product was purchased before 2010, the marking you find engraved does not correspond to a code, but you can trace the component to be replaced by following the coding system. To do this, read the steps in the guide to our labeling system.

Can I add a current component to an outdated Vivoil product?

Not always. Contact us and we will check together if it is possible.

Can I use a Vivoil component at low pressure?

If your component is a hydraulic pump: yes, you can.
If your component is a hydraulic motor or a flow divider: it depends on the pressure value and the product.

Can I use a Vivoil component at very high or very low temperatures?

Our catalogs indicate the reference temperatures for the use of Vivoil products. In general, our products work if:
• ambient temperature is between -20° and +60°.
• fluid temperature is between -15° and +80°
If the fluid temperature is higher than 80°, it is necessary to apply VITON seals.
If the fluid temperature is higher than 120°, we don’t have suitable solutions. 
In any case, for special needs you can contact our technical department.

Can I set the valve to a very low pressure value?

It depends on the flow rate passing through the valve. In Vivoil products it is not possible to set the valve below 10 bar.

What is the difference between hydraulic pumps and hydraulic motors?

Hydraulic pumps transform mechanical energy into hydraulic energy, while hydraulic motors transform hydraulic energy into mechanical energy.

What are the main constructive and functional characteristics that make hydraulic pumps different from motors?

Pumps and motors are made with components that have different tolerances, require a different type of testing and given the different function, where possible, provide a reinforced oil seal that resists better to back pressure.

To learn more, read our article Difference between hydraulic pumps and motors.

Can a pump be used as a motor and vice versa?

You cannot use a pump as a motor because the manufacturing tolerances required to make motors are different from those of pumps. Therefore, pumps may not have the efficiency and start-up capability needed to work properly as motors. Also, pumps are not tested to work as motors. Instead, you can use a motor as a pump because the tolerances are tighter.

I have noticed oil leaking from the gasket of the Vivoil pump or hydraulic motor I installed. What could be the cause of the leak?

Oil leaks can usually result either from a failure of the static seals, i.e. the gaskets, or the oil seal, or from the failure of one or more components. It is therefore important to understand if the damage only concerns the seals or if it is more widespread and involves the pump or the whole engine. In fact, in the first case, to solve the problem it will be sufficient to replace the damaged seal or oil seal, while in the second case it may be necessary to replace the entire pump or motor.
To learn more, read our in-depth analysis on what are the most common causes of oil leaks in hydraulic pumps and motors.

Questions and information about Vivoil flow dividers

How can I calculate the displacement of a flow divider if I only know the flow rate?

To calculate the displacement of a flow divider you must first define the flow rate of the individual element using this formula: 
single element flow rate = inlet flow rate/number of elements
and then define the displacement with this rough calculation:
displacement = flow rate of the single element/2000
Want to know more about it? We have written a guide to calculate the displacement of a divider knowing the flow rate.

Can I use a flow divider as a multiplier?

Yes, you can.  Want to know how? We’ve written a guide to using the divider as a pressure multiplier

What is the difference between KV flow dividers and RV flow dividers in the Vivoil range?

RV series flow dividers have replaced those of the earlier KV series. The products of the new version have the same function as the now discontinued one, but the two types are different in several aspects: dimensions, tolerances, precision, variants and components. To learn more, please read our article on the differences between the Vivoil KV and RV flow dividers.

Can I use an RV flow divider where a KV flow divider was mounted?

Yes, you can. There are differences in shape, size, and sometimes even differences in function between the two versions, but you can always find a suitable product.

Can I use water-glycol (HF-C) with Vivoil flow dividers?

No, it is not possible, because this fluid does not provide sufficient lubrication and consequently causes rapid deterioration in the performance of the divider.

What details are needed to add or remove an element to a Vivoil flow divider?

You can add or remove elements from a Vivoil flow divider but, to do so, we recommend that you contact our sales department because, depending on the number of elements, the fixing methods, the number of inlets and other details may change and require a case-by-case assessment.

What is the starting pressure of Vivoil flow dividers?

To start a flow divider, the inlet (or starting) pressure must always be at least 20 or 30 bar, under normal operating conditions (i.e., the flow rate listed as recommended in the catalog).
For higher than normal viscosities (greater than 68 cst) and when the number of flow divider elements is large or the flow rate is higher than recommended, the starting pressure values may be higher. In this case we advise you to contact our technical office to understand together which value is more correct to consider.

Is it possible to have flow dividers with valves with internal drainage?

Yes, it is possible, but not recommended, because internal drainage subjects the flow divider to stress. There is a way to transform the divider from external drainage to internal drainage, to do this you can consult our catalog of flow dividers.

Is it normal that the cylinders of the Vivoil flow divider I purchased do not rise at the same time?

It can happen. RV series flow dividers have their own accuracy. The physiological error in standard flow dividers is 3% for a load difference of up to 30 bar. Therefore, if the cylinders rise simultaneously within the 3% value, the product is compliant.
The MIA-FD series, on the other hand, is designed for large load differences and has an error of up to 2% with differences of up to 170 bar. 
If the error is greater than indicated, there are several possible reasons often related to the system or operating conditions. Contact us for an analysis of the problem.

Why don’t the cylinders of the flow divider go up at the same time?

There is a divider’s own error (3% up to 30 bar pressure difference at the outlets) related to construction tolerances.  In the case where the detected error is higher, the misalignment may depend on several factors. If you are interested in learning more, read the article on causes leading to misalignment of flow divider cylinders.

How do you adjust the valves of a flow divider?

It depends on the number of valves in your component. Therefore, we have written two guides to help you perform the calibration correctly. Here are directions for adjusting valves in single-valve RV flow dividers and in dividers with multiple valves.

Questions and information about Vivoil pumps

What is the difference between KV pumps and XV pumps in the Vivoil range?

XV series hydraulic pumps have replaced those of the previous KV series. From a functional point of view, the products are no different. From a performance point of view, however, the new series is improved over the previous one. To learn more about the features of the two series and their compatibility, please read our in-depth discussion: Differences between Vivoil KV and XV series hydraulic pumps.

Can I change the direction of rotation of Vivoil pumps?

Yes, you can. Read how in the guide on how to change the direction of rotation of Vivoil pumps.

Can I transform Vivoil single pumps into multiple pump elements and vice versa?

Yes, you can do this by replacing some components. To find out how, contact our sales department.

Can I convert a Vivoil pump into another type of pump from our range?

You can do this in some cases. It’s something that may require a lot of modifications and therefore may be economically too expensive compared to buying a new pump. To know more, contact our sales department.

Can I use water-glycol (HF-C) with Vivoil hydraulic pumps?

Yes, you can use water-glycol with Vivoil pumps but only under these conditions: the maximum speed must be 1100 rpm and alternatively the maximum pressure must be 170 bar, furthermore the maximum concentration of water-glycol must contain at least 50% oil.

Can I use edible oil with Vivoil hydraulic pumps?

No, this is not possible. In the food industry, they use stainless steel components and specific products, while Vivoil components are made of aluminum and steel.

Can I use mineral oil with Vivoil hydraulic pumps?

Yes, you can if it is mineral-based hydraulic oil HLP HV DIN 51524

Can I use water in your pumps?

No. Our pumps can only be used with oil.

Can I connect a Vivoil pump to one produced by another company?

No, it is not possible. Each manufacturer has its own standards and there are no normalized connections.

Can I add an XV component to a KV pump?

Not always. Contact us and we’ll check together to see if it’s possible.

What are the most common causes of pump body failure?

The causes that lead to a pump body failure can be diverse. Usually the most common are pressure spikes and cyclic loads, but by properly choosing the type of connections, performance and durability can be improved. Of the connections available, the so-called “cross” connection has the least resistance to cyclic loads. Other types are more robust. To learn more, read our article on the most common connections for hydraulic pumps.
There is also a special type of pump rupture, called a “V-shaped” pump. This is an infrequent and avoidable occurrence because it is due to pressure on the discharge pipe. To learn more you can read our article on what are the causes of V-shaped body rupture and how to prevent it.

Can I use Vivoil pumps at high rpm?

Yes it is possible, following the limitations indicated on the initial pages of the catalog. Above 2500-3000 rpm it is advisable to evaluate the use of VITON gaskets and increased connections according to displacement, viscosity and other parameters.

What is the difference between reversible (or bidirectional) pumps and Vivoil unidirectional pumps?

Reversibles (also called bi-directional or bisense), once installed, can rotate in two directions: either clockwise or counterclockwise. This is why they are used for special applications. Whereas, unidirectional ones, once inserted in the application, can rotate only in one direction or only in the other direction. Read our in-depth article to understand what the difference is between reversible and unidirectional pumps.

Is it possible to couple a primary pump equipped with a non-primary shaft (without a back spline) to a standard final pump ?

Yes, in some cases this is possible. The transfer of motion in these cases is through the driven shaft, and it is therefore necessary to change the configuration of the final pump to allow coupling. This connection, commonly referred to as “Z-Drive,” uses only the two pumps and additionally requires only the coupling kit.
Do you want to know how to make this coupling? We have created a video and a guide that illustrate the steps to follow: How to connect two stages of multiple pumps with a “Z-Drive” connection”.

Questions and information about Vivoil motors

Can I use water-glycol (HF-C) with Vivoil hydraulic motors?

Yes, you can use water-glycol with Vivoil engines but only under these conditions: the speed must be a maximum of 1100 rpm and alternatively the maximum pressure must be 170 bar, furthermore the maximum concentration of water-glycol must contain at least 50% oil.

Can I use edible oil with Vivoil hydraulic motors?

No, this is not possible. In the food industry, they use stainless steel components and specific products, while Vivoil components are made of aluminum and steel.

Can I use mineral oil with Vivoil hydraulic motors?

Yes, you can if it is mineral-based hydraulic oil HLP HV DIN 51524.

Can I use Vivoil motors at high rpm?

Yes it is possible, following the limitations indicated on the initial pages of the catalog. Above 2500-3000 rpm it is advisable to evaluate the use of VITON gaskets and increased connections according to displacement, viscosity and other parameters.

Can I use water in your motors?

No. Our motors can only be used with oil.

We are here to help you

Do you have any questions or need more information on the type of accessory to apply to your Vivoil pump, motor or flow divider? For any question or request please write, call us or read our FAQ