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Design

Float VS Electronic Fill Valves

By | Design, Level

Fill Valves are the heart of a tank-level control system (making the control panel the brain).  There are two common types of fill valves, Float, and Electronic, used in commercial building tank fill applications.  While both can be effective, the electronic float valves (and paired controls) provide extended life through even wear, improved communication with the BAS, and ease of service. 

Float vs Electronic Valves Tech Talk Transcription:

Hi, I’m Tim Zacharias with Cougar USA.

On this Tech Talk, we are going to cover the difference between the float style and electronic style fill valves for storage tanks. So in the city of Houston we have this code requirement where you have to go through an atmospheric storage tank before you add on a pressure boosting system.

To pressurize your building, you got two options on which type of fill valves, you would use for that tank. The style that’s been around for a long time, is going to be this one 2401 float valve from Cla Val using the 100-01 Hytrol valve, base valve configuration and we’ve got this CF1C1 Pilot assembly here that is controlling the water on, and off the valve to open and close it.Now, this is a mechanical assembly you got the float hanging down in the tank and literally just like the back of a toilet, you know, the float goes up the valve is going to turn off the flow goes down the valve is going to open up and refill the tank. Problem with these style valves is it’s mounted up on top of the tank it can be difficult and even dangerous to get in and service it and it’s all mechanical in terms of how you make any adjustments, how it turns on and off and when you have two of them, there’s no way to alternate which valve is the lead valve.

Now in general with Cla-Val valves like these you’re going to want to have regular water flow through the tubing and any pilot assemblies to keep them free of trash and debris. That’s going to ensure that the valve is going to open and close when you need it to. So we really moved away from the float style valves being our bassis of design, and our recommendation is going to be to go with this. The 136-01, the electronic style fill valve still using that 100-01 hytrol valve as a base valve, but instead of the mechanical pilot assembly, we’ve replaced that with an electronic solenoid. So, when were using this style of valve, we can put it into an assembly like this comes off of the top of the tank can be easily accessible safe to work on and we pair it with an electronic control panel, like a Cougar Systems Elite Series there that allows us to actually read the level in the tank and make our settings on the control panel there of when we want our valves to turn on and off when we want to get our alarms, as well as being able to alternate the fill valve. So every time, the tank Cycles to fill up, it’s going to switch which fill valve is filling the tank that’s going to give us that regular water flow through the valve and through the fittings, so that we don’t have any issues or get any trash or debris, things like that in there.

So when we’re working with the electronic series here, there are a couple of different options to consider that the two inch size and smaller, we are going to recommend that you do the 136-01 Series without closing speed control. So, closing speed control is a needle valve and the tubing, that allows you to restrict the water flow onto the top of the diaphragm and that slows down how fast the valve closes. and that is going to help reduce water hammer in the piping, but the two inch size dont really need it, and it can create additional restriction through the tubing in, in the solenoid, to be able to close the valve.

So don’t recommend the closing speed on the smaller ones, we get 2/3 inch and larger we are going to switch over to the 136 03 series and that’s going to have a larger solenoid to give you a little bit more water flow onto the top of the diaphragm as well as including the speed control to reduce the water hammer. We’re also using the epoxy coating and the stainless steel trim on these which can give you a longer life and wear on the valve body seat, things like that.

So those are going to be our recommendations again on the fill stations to go with the electronics series, The 13601 or 13603, and pair it with the electronic level control system like you see here in order to give you a lot more control and even wear on all the valves.

If You would like any more information please reach out or feel free to check out other Tech Talk videos.

Design Considerations for Pressure-Boosting Systems in Commercial Buildings

By | Design, Energy Savings, Pressure

More than 60 years ago, the late Dr. Roy B. Hunter developed a system for calculating water loads in commercial buildings. The estimated water demand of fixtures (water closets, sinks, etc.) is given a value called Fixture Units which have an equivalent demand load in Gallons Per Minute (GPM). The Fixture Units and Demand Load relationship is known as Hunter’s Curve and is still the basis for plumbing system design today.

Hunter’s Curve can be effectively used to calculate total system demand, but it has a glaring flaw. There is no consideration for diversity in the system demand. Using Hunter’s Curve for the basis of design of a Pressure Boosting System results in a pump system sized for all fixtures being used simultaneously, a scenario that will likely never happen. The pumps are grossly oversized for partial-demand conditions which make up 90% or more of total operation, causing poor system control and unnecessary wear on the pumps and piping system. In addition to Hunter’s Curve, Cougar USA uses field experience and data collection for system design.

To generate an accurate demand load profile, we gather as much information as possible about the building. The type of building has a huge impact on the load profile; even with similar fixture units, hospitals, hotels, schools, and office buildings will all have different load demands throughout the day and week. Special applications, the height of the building, locations of equipment, and potential future expansion are all factors in creating the right Building Load Profile. Once the system requirements are determined, we must make the right equipment selection.

Pressure Boosting Systems are typically comprised of two or more pumps, suction and discharge headers, control panel, and bladder tank. The pump style, size, and quantity and are all dependent on the Building Load Profile. For most commercial building applications, the small footprint and multi-stage design make the Grundfos CR Vertical Multi-Stage pump the best selection. The pump size and quantity will be determined by partial load performance and the redundancy desired. Typically, a higher quantity of smaller pumps is more efficient at partial load conditions without adding much to the initial system price when compared to a duplex (two-pump) system of larger pumps.

A properly sized and charged bladder tank is crucial to the overall performance of the Pressure Boosting System. Based on the load profile and building height, we can determine the size and location of the bladder tank. In low- to mid-rise buildings, the tanks will typically be installed at the pump system discharge. In high-rise buildings, the tanks will be installed on the upper floors, off the main riser.

The last consideration is the level of controls required for the building. Critical applications like hospitals, research facilities, and high-rise buildings will require control features like those on the Grundfos CU352 used on the Hydro MPC Booster System. A graphical user interface shows feedback of the system and any alarms, as well as advanced control features like Proportional Pressure Control, Reduced Operation for Emergency Power, Soft Pressure Buildup, and Communications for Building Management Systems.

To effectively design for today’s buildings, we must look beyond Hunter’s Curve. Cougar USA has made hundreds of Booster System selections for commercial buildings, and not once have we been wrong.