Nelson MR - How the Mini Regulator (MR) and Mini Regulator Drain Check (MRDC) Work; Normal Pressure Operation; Low Pressure Operation; Drainage After Shut Off

Nelson Irrigation Corp. 848 Airport Rd. Walla Walla, WA 99362-2271 USA Tel: 509.525.7660 Fax: 509.525.7907 E-mail: info@nelsonirrigation.com Web site: www.nelsonirrigation.com
MR/MRDC
MDC Guide
HOW IT WORKS
1.0 REGULATING WATER PRESSURE AND DRAIN CHECK
The purpose of this regulator is to adjust varying water pressure on the irrigation sprinkler, rotator or drip
irrigation system. The result is consistent flow and uniform irrigation. The MRDC also includes the drain-
check benefit for retaining the water in the irrigation pipeline that would otherwise drain out through the
lower sprinklers and create wet spots at the lowest area. The MDC model provides drain check as well but
is used only when regulation is not required. Both the MRDC and MDC restricts operation until adequate
pressure is available to irrigate properly.
2.0 HOW IT WORKS
The mini-regulator (MR) is normally open. The water pressure output is regulated. By contrast the mini-
regulator drain check (MRDC) and mini-drain-check (MDC) are normally closed. They will open only if
minimum operating pressure is provided. The different effect on Rotators is shown by these drawings of
three typical pressure conditions.
MINI REGULATOR (MR)
& MIN REGULATOR
DRAIN CHECK (MRDC)

Outlet (regulated
pressure)
Inlet (keep
pressure above
regulator rating)
2
MR/MRDC
PRESSURE RATING
OPTIONS:
20 PSI (1.4 BAR); 30 PSI (2.0 BAR)
35 PSI (2.4 BAR); 40 PSI (2.8 BAR)
45 PSI (3.1 BAR); 50 PSI (3.4 BAR)
FLOW RANGE:
0.5 - 5 GPM (1.8-18.9 LPM)
(flow
not regulated)
(flow
not regulated)
With adequate pressure, the MR and MRDC regulate
to design pressure but the MDC is open fully and does not regulate.
(flow
not regulated)
With low pressure, the MR is open, the MRDC and MDC are closed to draining.
With no pressure, the MR is open, the MRDC and MDC are closed to draining.