Guide · Faucet head assembly
Drip faucet head assembly: the parts, the threads and the maker's order
The parts of a drip faucet head, one maker's documented order and why it is not a rule for every brand, thread matching, and the cautions makers state.
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Short answer
A drip faucet head usually has a backflow device, a filter, a pressure regulator and a tubing adapter. Follow your kit maker's order and thread notes, because makers do not all use the same order. Mister Landscaper documents one order for its system; we found no source that sets an order for every brand.
What each part does
A head assembly is the chain of parts between the outdoor faucet and the drip tubing.
- Backflow device. Keeps garden water from flowing back into the drinking water supply. Which device you need is set locally; see the backflow guide.
- Filter. Catches particles that would clog emitters. The filter mesh guide covers mesh ratings.
- Pressure regulator. Brings faucet pressure down to what the drip parts are rated for. See the regulator guide.
- Tubing adapter. Joins the last threaded part to the drip tubing.
Some parts combine two jobs. DIG's D54 is a filter and pressure regulator in one body, with a 150 mesh stainless steel screen, preset to 25 PSI.[1] See the D54 page.
One maker's documented order
Mister Landscaper says a brass backflow device needs to be the first item attached to the faucet in its system.[2] Its FAQ lists the full order from the faucet as backflow device, timer, pressure regulator, 150 mesh filter, then the poly faucet fitting.[2] It also warns that a regulator installed before the timer can build up excessive pressure.[2]
That is the order for the Mister Landscaper system. We could not read DIG's 2025 drip guide, which sets out DIG's order, so we give no DIG order and no general rule.
Does the regulator go before or after the filter?
In Mister Landscaper's system, the regulator comes before the filter.[2] Other makers combine both in one body, like DIG's D54, which settles the question for that part.[1] For any other kit, follow the order in its own instructions.
Threads: hose to hose, female to male
The parts screw together, so each joint needs matching threads. DIG's D45 backflow preventer has a 3/4 in female hose thread inlet and a 3/4 in male hose thread outlet.[3] DIG's D57A screen filter is also 3/4 in FHT by 3/4 in MHT, with a 155 mesh screen.[4] Parts like these chain together, each male end into the next female end.
Not every head part is hose thread. DIG lists its D54 with 3/4 in MNPT, a pipe thread, on both ends.[1] A pipe-thread part needs adapters to join a hose-thread chain. The thread guide explains FHT, MHT, FPT and MPT, and hose thread connections lists what meets what.
Raindrip's washer notes
In Raindrip's faucet assembly, the filter washer goes inside the faucet connection, and the flow control goes inside the swivel adapter with its black rubber washer facing up.[5] Those notes are for Raindrip's own parts.
Constraints the makers state
- DIG's D54 installation steps say to make sure the unit will not be under constant static pressure.[1] So it should not sit on a faucet that stays on with the line closed downstream.
- Mister Landscaper says its regulators should not be used inside a house or anywhere a leak might damage something.[2]
- Mister Landscaper says its backflow prevention valve has relief holes to reduce pressure, and that some water draining from them is normal.[2] That is a statement about its own valve.
Can I leave the regulator on the faucet all the time?
Not every regulator. DIG says its D54 must not be under constant static pressure.[1] Read your regulator maker's page for the same warning. In winter, Rain Bird recommends unscrewing filters, pressure regulators and backflow preventers, cleaning them and storing them indoors in a dry place.[6] See winterizing drip irrigation.
Head parts that fit this decision
Picks that fit3 products
Choose the Rain Bird FCKIT-1PK if you want the head parts in one box. Choose the Orbit 67738 3-in-1 (3/4 in FHT inlet to a 1/2 in Drip-Lock outlet) for a filter and regulator in one part, then add the backflow device your utility requires.
More on choosing
Choose the Rain Bird HT07525PS (3/4 in FHT x MHT, 25 psi) for a hose-thread regulator.
3-in-1 faucet adapter for Drip-Lock
Orbit 67738 3‑in‑1 faucet adapter (3/4 in FHT, 150 mesh filter, 20 psi regulator, 1/2 in Drip-Lock)
Hose-thread pressure regulator
Rain Bird HT07525PS 3/4 in FHT x MHT 25 psi pressure regulator
On Amazon, check that "Ships from" and "Sold by" show Amazon.com or the brand before you order.[8]
Next
Questions
What order does a drip faucet assembly go in?
Your kit maker's order. Mister Landscaper lists backflow device, timer, regulator, 150 mesh filter, then poly fitting for its system; we found no source that sets one order for every brand.[2]
Does the pressure regulator go before or after the filter?
It depends on the maker. Mister Landscaper puts the regulator before the filter, and DIG's D54 combines both in one body.[2][1]
Why does water drip from my backflow preventer?
Mister Landscaper says its backflow prevention valve has relief holes and that some water draining from them is normal. For other devices, check the maker's instructions.[2]
Can I leave the regulator on the faucet all the time?
Not every regulator. DIG says its D54 must not be under constant static pressure, and Rain Bird recommends taking head parts indoors for winter.[1][6]
Who decides what backflow device I need?
Your water utility or local plumbing authority. The EPA says programs vary by state and municipality.[7]