Forum Post: Modelling a Pelton

I am modelling a hydro station with 4 pelton units for pressure rise and mass surge.

I have currently modelled these as a discharge to atmosphere element as is recommended in the Hammer knowledge base. However, using a discharge-to-atmosphere element, it is possible to model multi-stage closure? Ie define a closing relationship that contains several different closing rates?

Is the only alternative to model this as a TCV element? If this is the case, how can I set up the model so that it is still discharging to atmosphere without downstream pipe-work, reservoirs etc?

Thanks for your help.