FAQ

10 QUESTIONS TO CHOSE THE RIGHT ISOLATION VALVE

TALIS OFFERS A WIDE RANGE OF ISOLATION VALVES. BELOW, YOU WILL FIND SOME TIPS THAT CAN HELP YOU TO CHOOSE THE RIGHT VALVE FOR YOUR INSTALLATION.

Is full bore a must in the installation?

Then, gate valves GV or ball valves BV are the best options. When the valve is open, the path is totally free and creates no obstacle to the water.

Do you need to minimize the head losses in the installation?

For the same reason as above, GV or BV are the best options, as they create really low head losses in the installation.

Do you have dimensional limitations?

In this case, take into consideration that the height of a gate valve is always bigger than that of a butterfly valve. Depending on the DN, it can even be three times the DN! So, for installations with space issues, butterfly valves are usually the best option. Double eccentric butterfly valves DEBV have a longer distance between flanges than centric butterfly valves CBV. This last type can be installed in those installations with really limited space.

In what kind of installation will the valve be installed?

If you need to do an overhead installation, all GV, DEBV and CBV are suitable. The same applies to chamber installations. On the other hand, if the installation is underground and the valve has to be buried, the best options are GV or DEBV. Both can withstand the bending forces that can occur with ground movements.

What is the pressure of the network?

For PN10 and PN16, CBV can be a good solution, as well as GV (this last type even up to PN25). If the pressure is higher, DEBV can offer solutions up to PN40. And for really high pressures, TALIS offers BV that can reach PN160.

Will the valve be used only for isolation purposes?

As isolation valves, GV are designed to work in on/off applications. On the other hand, butterfly valves can regulate the flow under some pressure and flow circumstances. Then, if you need to do some regulation, butterfly valves can be installed, though control valves are better for that purpose.

What kind of media do you have to transport?

All our valves are designed to work entirely safely for water applications. However, for sewage media, GV are the best option, always choosing the materials accordingly. On the other hand, for very specific fluids such as chemical media or food, the best option is CBV because by choosing the right material for the liner and the disc, the valve will be ready to transport those fluids in total safety.

Is pneumatic actuation required?

Pneumatic actuators can be easily installed on butterfly valves. TALIS offers also a solution for GV, but has to be requested in advance because the configuration of the stem and the internal part of the valve is different.

Do you need high speed of actuation?

In this case, CBV is the right choice because they can be operated with a quarter turn of the disc. While DEBV are also operated by a quarter turn of the disc, the number of turns to open or close is higher because of the gearbox that reduces the operating torque. This way, water hammer is controlled. GV in general have longer operation times because the number of turns to open or close the valve is bigger.

Will the valve be installed end-of-line?

In that case, all our isolation valves will fit the purpose. CBV can be installed end-of-line if a counter-flange is used, in order to avoid any movement of the liner that could create a risk of leakage. 

 

12 QUESTIONS TO HELP YOU TO CHOOSE THE RIGHT CONTROL VALVE

 

What is my application?

Water (treatment, transmission and distribution), Irrigation, Fire protection, Industry, Dams and Hydropower.   

Comments: Except Fire Protection which requires RAF and specific approvals, and RAF-P only suitable for Irrigation, all applications can be controlled by the full portfolio.

What is the parameter I want to control: Pressure – Level – Flow?

Remember that control valves allow the control of one, two or three parameters at the same time. Most of the time, one parameter is chosen, but considering the TALIS Control Valve range, solutions are quite unlimited.    

What is the diameter of the installation (before sizing the control valve)?

The basis to work on the project despite the fact that TALIS Control Valves potentially allow a smaller diameter.

Comments: some Automatic Control Valves are unavailable from a certain diameter. For example, RAY range is [50 to 250mm] and RAF range is [40 to 400mm]: if you work with pipes DN1000, no need to consider these types.

What is the nominal pressure of the installation?

Sometimes, installations are made in a higher nominal pressure than normally requested. In order to avoid any disappointment (especially when the project is to replace another component), it is important to get the right connections!

Comments: If PN16 is available for all the TALIS Control Valve range, PN25 and PN40 can be approached with Hydrobloc/ Monostab/G Type and Needle valves/Flow Control. More than PN40? Needle valves and G Type are the answers.

What are the maximum and the minimum pressures at the inlet of the control valve I want to install?

The maximum pressure will help to define the right PN and partially the size of the control valve. Do not forget that inlet pressure may vary (head losses in a network due to the flowrate, leaks, level in a reservoir or a dam etc...).

What is, or will be, the outlet pressure or the min and max outlet pressure?

Most of control valve deliver the flow at the same outlet pressure (which can be adjustable as it is possible on a TALIS Pressure Reducing Valve). Sometimes, outlet pressure may vary (level in the reservoir to fulfill, high temporary consumption in an industrial area or farmland area etc…).   

Comments: these criteria are important to analyse cavitation risks and also opening curves. If Needle Valves are especially dedicated for high operating conditions, Hydrobloc with anti-cavitation device and G Type are also a right alternative.

What are the lowest flowrate (can be 0) and the highest flowrate?

Lowest flow is not an issue generally. All TALIS Control Valves are watertight at no flow rate. But it could be taken into account when the project requires a specific design or to confirm cavitation risks. Regarding highest flowrate, it is important to consider the velocity in the control valve and also head losses generated in itself.

Power supply on field or not?

TALIS Automatic Control Valves do not require a power supply. But it is necessary for actuated control valves or electrical control valves working with solenoid(s).

Comments: Generally, when control is provided by an automate, electricity is present. Except Monostab which cannot be actuated, TALIS Automatic Control valves can be controlled with low voltage (from 6V) while Actuated Needle Valves and Flow Control require 230V or 400V.

Do I want an actuator?

Different actuators are available, electric, pneumatic, hydro-electric, float electric etc…

Whatever the type of actuator, there are also automatic controllers (with or without remote control) and, optionally, sensors. From these, numerous control possibilities can be achieved. TALIS teams help you in order to choose the right actuator and the right control valve regarding what you want to do.

Comments: generally, these type of actuators are dedicated for Needle Valves and Flow Control.   

Do I want a manual command?

Manual command is available for the whole full range, except for direct acting control valves (technically impossible). We consider 2 types of manual command:

_Permanent manual control.

_Safety manual command (in case of problems on the network, emergency or malfunction).

Comments: by its flexibility, TALIS range offers a significant number of options for all types of Control Valves, except Monostab (technically impossible).   

Do I want an automatic system power free?

If yes, TALIS automatic control valves work with fluid pressure only and provide a solution to meet your request.  

If no, step by step, electric or actuated TALIS control valves also provides a solution.

Do I have to consider another critical point? (can be to sustain the inlet pressure, ensure automatic closing or opening in case of power fail, or provide additional security)

Sometimes the main function of TALIS Control valves is so important that additional functions (such as security against power failure or low pressure) are overlooked. Work with our teams to see if additional equipment can be integrated. And keep in mind that simplicity is often a key success factor in network system operations.

Product catalogue E-VERSION

Address Details

BELGICAST Internacional, S.L.
Bº Zabalondo, 31
48100 Mungia (Bizkaia) - Spain
Tel: +34 94 488 91 00
Fax: +34 94 488 91 25
belgicast@remove-this.talis-group.com