1. General information

The research for innovative solutions to handle fluids under different conditions with only one valve was the most ambitious

challenge of the Valpres research and development department: one trim capable to handle the control of fluids both in the

liquid and in the gaseous state.

Valpres patented solution provides technical benefits and high performances in all process conditions.

The VP1-L trim, (for liquids) has the feature to better manage moderate and severe cavitation while the VP1-G trim (for gas

and steam) offers excellent results in reducing the noise. These standard trims are able to manage the process even under

difficult conditions and severe service. Furthermore, the same basic geometry is used with both liquids and gases allowing product

standardization. The principle of curved plates (Fig. 1-3) provides excellent throttling performance in terms of FL, sigma and XT

coefficients without sacrificing the maximum capacity of the valve. Also the minimum flow rates have been carefully evaluated

by technicians and engineers to ensure the best rangeability. The Valpres trim are designed to be installed both on floating and

trunnion ball valves. Valpres control valves can be designed full or reduced bore according to process conditions.

1. Informazioni generali

La ricerca di soluzioni innovative per la manipolazione di fluidi nelle diverse condizioni operative racchiuse in un’unica valvola è

stata la più grande ambizione del lavoro di ricerca e sviluppo di Valpres. Un solo trim in grado di gestire il controllo di fluidi sia allo

stato liquido che allo stato gassoso.

La soluzione, brevettata da Valpres, fornisce benefici ed alte performance in tutte le condizioni di processo.

Il trim VP1-L (per liquidi) ha la caratteristica di poter meglio controllare situazioni di cavitazione, da moderata a severa, mentre il

trim VP1-G (per gas e vapore) offre risultati eccellenti nell’ attenuazione del rumore. Questi trim standard sono costruiti con la stessa

filosofia costruttiva siano essi per gas e per liquidi al fine di ottenere una uniformità di prodotto e meglio servire i nostri clienti.

Il principio utilizzato, piatti curvi inseriti all’interno della sfera (Fig. 1-3), fornisce eccellenti performance in termini di coefficienti FL,

sigma ed XT senza tuttavia sacrificare la portata della valvola. Allo stesso tempo anche le portate minime sono state accuratamente

valutate dai tecnici e dagli ingegneri al fine di garantire il miglior rapporto tra portata massima e minima.

I trim Valpres sono stati progettati per essere installati sia in valvole

flottanti che trunnion. Inoltre, le valvole di controllo valpres

possono essere fornite sia in esecuzione a passaggio pieno che ridotto.

2. Main technical features

VP1 valves are sized according to IEC 60534 and ISA75 international sizing equations.

Customized calculations and CFD can be adopted for special applications. Valve sizing is performed with latest generation

VALPSIZETM 2.0 sizing tool.

• Noise is evaluated according to customized IEC and VDMA equations.

• Venturi outlet closures can be adopted to better control velocity pro

files in steam/gas applications.

• Valve body construction and flanges can be manufactured according to customer speci

fications. Floating and trunnion control ball

valves replicate the standard features that are implemented in the on-off valves.

• Materials: solid metal alloys can be adopted as well as weld overlays in Corrosion Resistant Alloys (CRA).

• Metal to metal seal contact is available as a standard solution, leakage rate Class V. Soft seated valves are for clean fluids and

tight shut off applications.

• Special plates design and high peak frequencies allow standard noise reduction up to 20dB(A) thanks to velocity control (Fig. 6).

• Liquid Recovery Factor up to 0.96 thanks to special plates design and multiple pressure drop stage (Fig. 7-8).

• Real rangeability up to 200:1 with standard trim. Customized trim can be adopted to increase the rangeability to 300:1 and above.

• Resistors can be installed to increase valve’s performances when required 30dB(A) noise reduction can be reached with

combined solutions.

• High Inherent Cv value (i.e. VP1-L 4” with Cv=500 vs globe valve 4” with Cv=160-200: this implies that an 8” globe valve is

required to compare the capacity) (Fig. 9).

• VP1 valves are intrinsically self-cleaning trim and they are suitable to handle 2-phase fluids, pulp, flashing liquids and dirty fluids.

• Cryogenic and high temperature design is available.

• VP2 design is available for special and very severe applications.

• VP Valpres are also available with V-shaped ball in the following standard design see (Fig. 10).

Customized V-shape balls are available upon request to better respond to the required process conditions. Various type of liquids,

gasses and steam can be controlled by these valves.

Soft seats are standard. Metal to metal seats are available for high temperatures and dirty or slurry conditions.

All the valves are full rated.

2