The ASEPCO Weirless Radial-Diaphragm Takeoff Valve Family is suited for any critical CIP/SIP application where a “tee” and its associated dead leg must be eliminated. Key applications include: point of use or “drops” for pure waters (including WFI) as well as sampling, draining, transferring, or diverting from a line or manifolds. The two ASEPCO valves in this family are the Point-of-Use Valve and the Zero Dead Leg Valve. Below, we’ll show you how your colleagues are using these ASEPCO Takeoff Valves in their applications. The key here is that they end dead legs!
So, what exactly is a dead leg? A dead leg is a sump or area of stagnation in the piping system where process solutions and particles will lodge. (As defined in the ASME BPE: dead leg — an area of entrapment in a vessel or piping run that could lead to contamination of the product.)
The longer the distance from the valve seat to the main pipeline, the worse the dead leg issue. In fact, more than 2 pipe diameters is typically considered a dead leg. That means on a 0.5-inch outer dimension (OD) pipeline (with the typical inner dimension of 0.37 inch), it only takes .74 inch to be considered a dead leg! (See Drawing #1a below for an example.)
Dead legs take longer than other areas to flush out during CIP, which extends rinsing cycles that create “cold spots” during SIP and increase downtime. This increases both validation and production costs, because dead legs slow and complicate attempts to clean and steam sterilize systems effectively and rapidly.
All the valves in the ASEPCO Takeoff Valve Family are designed without the “tee”, completely eliminating any dead leg. In these valves, the diaphragm seats flush to the outer dimension of the piping. The “spool piece” part of the valve becomes part of the main pipeline (or run), while the outlet of the valve (or branch) is perpendicular to it. The run is therefore unaware of the presence of a valve. The result is that there is no dead leg in which dangerous bits of stuff can become trapped. Flow to the outlet or branch line only occurs when the valve is opened.
So how flush is “flush”?
In Picture #1b and #1c above, you can see a complete Zero Dead Leg Valve and a close-up of the seat. The seat is as flush as physically possible, because it is located at the point where two arcs intersect. Note how flush the seat is in Picture #1c. This degree of flushness is not possible in the “Zero” configurations of weir-diaphragm valves.
One of the simplest ways to dramatically improve the performance of any critical piping system is to eliminate all dead legs. Only the ASEPCO Zero Dead Leg and Point of Use Valves have the diaphragm valve seat located directly at the pipeline wall in all configurations. It is the only aseptic valve in industry that makes this possible in a tough configuration like a 3-inch OD spool piece and 0.5-inch OD outlet. These valves accommodate piping from 0.5 inch to 4.0 inches OD.
Now, where in piping systems do dead legs really get in the way? There are three common problems that Takeoff Valves solve routinely:
- Water drops or points-of-use
- Sampling from a line
In Drawing #1d below, different Take Off Valves are featured in each of these applications. As you can see, if there were a “tee” and dead leg located at each of these points, the inherent CIP/SIP nature of the piping system would be compromised
#1d: General catalog reference number for all ASEPCO Takeoff Valves: KW*-510 (*indicates spool size options)
In addition to eliminating dead legs, another reason why ASEPCO valves are an excellent choice throughout your piping systems is because ASEPCO valves seal every time with a simple clamp. This reduces maintenance costs 80% compared to weir-diaphragm valves.
ASEPCO Valves end the messy time-consuming use of torque wrenches, bolt patterns, lost gaskets, and lost bolts that wreak havoc in the lives of people responsible for the perfect functioning of a process system. After all, haven’t you seen your best people expend all that energy on a valve only to find it leaking on the floor? And if it’s leaking, the seal obviously isn’t intact.
And if the seal isn’t intact, your system can get contaminated right? Of course, when a valve is specifically designed for biopharma applications, is machined from 316L bar stock, and seals perfectly. It does cost more, but every time you use it you save money and hassle.
Remember, to change a diaphragm on a weir valve takes 15 minutes, with an ASEPCO valve it takes 1 minute and requires no tools. Weir-diaphragm valves might cost a bit less up front, but you pay more forever afterward to use them, and this does add up. And if getting operating costs down is part of your job, this is worth thinking about.
ASEPCO Weirless Radial-Diaphragm Takeoff Family Valves share these features:
- Valve seat is flush with process line
- Excellent cleanability
- Integral travel stops that never need adjusting
- Fits into tight piping areas
- Change the diaphragm in under a minute without any tools
- Drains completely