Product group 04
The most numerous but least considered item in an installation. A wrongly selected valve either locks up the line or quietly wastes energy for years.
Flanged butterfly valve · disc, shaft and handwheel cross-section
Why it matters
A valve doesn't just open and close; it segments the line, distributes flow and protects the equipment. A properly designed fittings group also makes maintenance easier.
If an isolation valve is placed before and after every piece of equipment, removing a pump or exchanger doesn't require draining the entire system. This setup makes a small difference in upfront cost and a very large one in operation.
Among circuits connected to the same manifold, the closer one draws too much water, the farther one too little. Lower floors overheating while upper floors stay cold is, more often than not, a balancing problem rather than a boiler problem.
When a pump stops, water flows back; the surge on the next start-up strains the pipe and fittings. The right check valve type prevents that surge from the start.
Installation debris, weld slag and corrosion particles damage a pump impeller or exchanger plate the most. A filter is the cheapest insurance item you can buy.
It's the one element that opens when pressure rises in a closed circuit. Its set pressure and capacity are determined by calculation — never chosen arbitrarily.
Pump and motor vibration travels along the pipeline, loosening connections and causing noise. A flexible connection cuts that vibration off at the source.
Types
Grouping valves into three categories by function makes selection much easier.
For opening and closing the line. Butterfly is economical at large diameters; ball provides full tightness at small diameters.
A valve type that cuts through and fully shuts off solid-laden, fibrous or heavy-duty fluids. Preferred in wastewater, sludge, mining and powder conveying lines.
For distributing flow rate in a measured way. Eliminates imbalance between circuits.
Protects equipment from backflow, dirt and overpressure. Small items that prevent big damage.
Selection criteria
Once eight items are clear, both the type and the model are determined.
Function type
Isolation, control, or protection? Trying to control flow with an isolation valve wears out both the valve and the line.
Isolation / control / protection
Nominal diameter
Based on pipe diameter. Selecting a valve smaller than the line unexpectedly increases pressure loss.
DN size
Pressure class
Based on operating pressure and static pressure. In high-rise buildings, the lower floors are decisive.
PN6 / PN10 / PN16 / PN25
Fluid and temperature
Water, glycol, steam or a process liquid. Temperature directly determines the sealing element's material.
Fluid + °C
Body and seal material
Cast iron, steel or stainless body; EPDM, NBR or PTFE sealing. Compatibility with the fluid is essential.
Body + seal type
Connection type
Flanged, threaded, wafer or welded. Based on the existing installation and mounting clearance.
Flanged / threaded / wafer
Actuation type
Handwheel, lever, gearbox, or actuator. If it will be connected to automation, the signal type is also needed.
Manual / pneumatic / electric
Sealing class
Allowable leakage in the closed position. Specified separately for critical lines and gas applications.
Sealing class
You don't need all of it. We'll work out anything missing together with you.
Create a quote requestFAQ
The four questions we hear most often at the quote stage.
Diameter is decisive. Below DN50, a ball valve is both more economical and fully tight. From DN50 up, a butterfly valve wins out on space, weight and cost. Both are isolation valves; neither is designed for flow control.
In the short term, yes — but it's not the right approach. An isolation valve left half-open both wears out and produces noise and vibration. A balancing valve with a measurement point is used for flow control instead; it gives a setting that's both lasting and repeatable.
Static pressure factors in just as much as operating pressure. In the basement of a high-rise building, even if system pressure looks low, the water column alone produces significant static pressure. Tell us the building height and we'll determine the class; in borderline cases, stepping up to the next class is the right call.
Right before the equipment you want to protect: at a pump's suction, an exchanger's inlet, or ahead of a control valve. Service clearance needs to be left below and beside it so the strainer basket can be removed; this detail is often overlooked during installation.
Next step
Share your line diagram or material list, and let's fill in the gaps and price it together.