Dramm - PCAS Pressure Compensated Emitter
Brand: Dramm
PCAS Pressure Compensated Emitter
PCAS emitters hold their rated flow across a wide pressure band, so the first pot on a bench and the last one on the run get the same volume. Dramm rates them from 15 to 50 psi at the dripper and recommends keeping at least 25 psi at the manifold so the last dripper still sees the minimum after line loss. The compensating element is a chemical tolerant silicone diaphragm, and Dramm has deliberately made the body larger than its previous emitter so the labyrinth is wider and passes debris instead of trapping it.
Two things to choose. Flow rate is the horticultural decision: 2 lph (1/2 gph), 4 lph (1 gph), 8 lph (2 gph) or 12 lph (3 gph), delivered at that rate anywhere in the 15 to 50 psi window. Outlet is the plumbing decision and is not cosmetic. A barbed outlet pushes straight onto 0.191 in OD leader tube, and it is what the 2 lph comes as; PressFit is a barrel outlet, which is how the 8 lph and 12 lph come, and it reaches Dramm 192 tubing through the MAN1 barrel-to-barb adaptor. The 4 lph is the one flow offered both ways. Read the insert colour with the outlet style, not on its own: black is 2 lph barbed, green is 4 lph, red is 8 lph and black again is 12 lph PressFit, so colour alone does not identify a flow rate already in the house.
Specifications
| Flow rate by option | 2 lph (1/2 gph), 4 lph (1 gph), 8 lph (2 gph) or 12 lph (3 gph) |
| Operating pressure | 15 to 50 psi at the dripper |
| Recommended manifold pressure | At least 25 psi, so the last dripper still sees the minimum after line loss |
| Outlet by option | Barbed on the 2 lph and one 4 lph; PressFit barrel outlet on the other 4 lph and on the 8 and 12 lph |
| Insert colour by option | Black on 2 lph barbed; green on both 4 lph; red on 8 lph; black on 12 lph PressFit |
| Barb fits | 0.191 in OD micro tubing |
| Diaphragm | Chemical tolerant silicone |
| Anti-clog design | Oversized body with a wider labyrinth so debris passes rather than lodging |
Configurations
| Flow Rate | Outlet | Part number |
|---|---|---|
| 2 lph - 1/2 gph | Barbed - Black Insert | PCAS2L |
| 4 lph - 1 gph | PressFit - Green Insert | PCAS4L |
| 4 lph - 1 gph | Barbed - Green Insert | PCAS4LB |
| 8 lph - 2 gph | PressFit - Red Insert | PCAS8L |
| 12 lph - 3 gph | PressFit - Black Insert | PCAS12L |
Key Features
- Pressure compensated from 15 to 50 psi, so elevation change and friction loss stop mattering
- Wider labyrinth in a deliberately larger body reduces clogging
- Silicone diaphragm chosen to tolerate the chemicals a greenhouse puts through a line
- Four flow rates with Dramm's own gph equivalents, so the flow decision is per crop not per system
- Barbed and PressFit outlets so the emitter suits either leader tube or a manifold build
- Colour-coded inserts make an installed emitter identifiable at a glance
Ideal Applications
- Hanging basket lines where every basket must get the same volume
- Potted crops on long runs where friction loss would otherwise starve the far end
- Benches with elevation change
- Retrofitting even watering onto an existing non-compensated line
Pairs with 0.191 in micro tubing, slim weights or EasyClean stakes at the pot, micro valves for individual shut-off, and MAN1, MAN2 and MAN4 manifolds where one emitter serves several pots.
Choose options