Clippard MAR-1PK-3 Miniature Pressure Regulator, 10-30 psig

The Clippard MAR-1PK-3 is a knob-adjusted miniature regulator from the MAR-1 family that Clippard introduced in 1962 as a simple, robust and cost-effective regulator in a small package. Decoded with the data sheet order table, it has a 1/8 inch NPT male inlet and a #10-32 female outlet (MAR-1P), a plastic adjustment knob (K) and a 10 to 30 psig outlet range (-3). Clippard’s online parts list shows the same item as MAR-1KP-3, ordered as MAR-1PK-3.

A brass workhorse regulator for small air circuits

Where the DR-2 is chosen for tight set point, the MAR-1 is chosen for ruggedness and value. The body is brass with nitrile seals and a stainless steel stem and spring, the adjustment is a knob with a 40-pitch micro-adjust thread, and the whole regulator weighs 0.18 lb. It is offered in relieving and non-relieving versions: relieving types hold the outlet constant when downstream conditions change, while non-relieving types have no vent to atmosphere, can run on compatible liquids and let the outlet pressure rise after a downstream event.

The -3 suffix limits the adjustment band to 10 to 30 psig, which is a practical choice when a circuit should never be set above its design pressure by an operator turning the knob.

Specifications from the data sheet

Ordering code and mounting variants

Order codes follow the pattern base model, adjustment type, relieving option, pressure range; the data sheet example is MAR-1BPF-5. MAR-1 is #10-32 female both ends, MAR-1P is a 1/8 inch NPT male inlet, MAR-1M is a #10-32 manifold style, MAR-1C is #10-32 female at both ports, MAR-1CP has a 1/8 inch NPT male inlet with a #10-32 female outlet, MAR-1R is the cartridge style and MAR-1BP has 1/8 inch NPT at both ports. Adjustment letters are blank for a knurled knob, K for a plastic knob, F for a screwdriver slot and C for a plunger style (available in relieving form on MAR-1 and MAR-1P only). Non-relieving (NR) is not available with the plunger option. FKM seals and electroless nickel plating are available as options, so confirm those before ordering for an aggressive medium.

Installation notes

Fit the regulator through its #15/32-32 mounting thread with the nuts and lockwashers furnished, pipe the 1/8 inch NPT inlet from a filtered supply of no more than 300 psig, and set the knob against a gauge fitted downstream. Because the outlet range tops out at 30 psig, size the downstream gauge for the same band. Keep temperature inside 32 to 230 F; in hot enclosures such as outdoor skids in summer, keep the body clear of heat sources.

Typical uses and related products

Bench instrumentation, pneumatic cylinders on small machinery, spray and dispensing heads, air springs and pilot-pressure supplies are typical jobs for a miniature regulator. See the Clippard DR-2 for repeatability to 0.25 psig and the Cordis controller for signal-driven set points, or browse the wider Regulators range. Neither the data sheet nor the part page prints hazardous-area approvals for this regulator, so none are claimed here.

How the MAR-1 compares with the DR-2

Both regulators come from the same Clippard line and share flow behaviour, so the choice is about accuracy, materials and adjustment. The DR-2 data sheet gives a typical repeatability of 0.25 psig, an electroless-nickel-plated body, FKM seals with PFPE lubricant, a 5/16-24 mounting thread and a 2 to 100 psig range. The MAR-1 has a brass body, nitrile seals as standard, a #15/32-32 mounting thread, a 10 to 100 psig range in its unsuffixed form and no repeatability figure printed. Choose the MAR-1 where cost and ruggedness matter more than set point accuracy, and the DR-2 where the set point is the product. The two use different mounting threads, so a drilled panel cut for one will not take the other without rework.

MAR-1PK-3 questions

What outlet pressure range does the MAR-1PK-3 cover?

The -3 suffix gives a 10 to 30 psig adjustment range. The maximum input pressure is 300 psig.

How much air can it flow?

The data sheet lists 3 scfm at 50 psig and 5 scfm at 100 psig; the Clippard part page converts these to 85 and 140 l/min.

Why is it listed as both MAR-1KP-3 and MAR-1PK-3?

Clippard’s part page shows MAR-1KP-3 and says to order it as MAR-1PK-3, which follows the data sheet order pattern of base model P, adjustment K, then range -3.

Can it be used with water or oil?

Only non-relieving (NR) versions are listed for water or oil; this relieving model is for air.

What seal material is standard?

Nitrile seals are standard, and FKM seals are optional with the -V designation.

Using it in Oman and the GCC

Supply the regulator with clean, dry, filtered air, as compressed air in hot and humid coastal plants often carries water and dust that shorten the life of small pneumatic parts.

Information to send with an enquiry

• Outlet pressure range and quantity

Documents and quotation

The MAR-1 data sheet is available to download from this page. Seven Star LLC supplies Clippard regulators from Muscat; quote the complete part number and quantity when requesting a price.