The Miljoco-Weiss LF4UGY1-V30-4L is a Weiss process pressure gauge with a 4-1/2″ dial, a 30″Hg-0-30 psi compound range and a 1/4″ NPT lower connection.
The Weiss LF4UGY1 is a 4-1/2″ process pressure gauge with a black fiberglass reinforced PBT case of solid front construction and a blow out back safety design.
It uses a brass socket with a phosphor bronze C tube and silver brazed joints.
Specifications on this page are taken from the Weiss LF4UGY1 / LF4UGY2 submittal drawing; Weiss Specialty Pressure Gauges catalog; Weiss UGY process gauge instructions. Verified 2026-09-11.
Warranty
Miljoco-Weiss warrants its products to be free from material defects in material and workmanship for 12 months from the date of shipment, or such other period as provided in the product documentation, per the published Miljoco-Weiss terms and conditions of sale (Section 15, Limited Warranty).
Key Features
Solid front, blow out back
Fiberglass reinforced PBT case with solid front construction and blow out back safety design.
0.5% accuracy, Grade 2A
ASME B40.1 Grade 2A.
Dual scale psi/kPa dial
4-1/2″ dual scale dial.
Brass and bronze wetted parts
Brass socket, phosphor bronze C tube, silver brazed.
Micrometer adjustable pointer
Black aluminum pointer, micrometer adjustable.
Technical Specifications
| Model | LF4UGY1-V30-4L |
| Type | Process pressure gauge, liquid filled |
| Ordering Code | Series LF4UGY1, range 30 inHg-0-30 psi, connection 1/4 in NPT lower |
| Range | 30″Hg-0-30 psi |
| Dial | 4-1/2″ dual scale psi/kPa |
| Case | Black fiberglass reinforced polybutylene terephthalate (PBT), solid front construction, blow out back safety design |
| Ring | Reinforced polypropylene |
| Window | Tempered glass (shatter proof glass or acrylic available) |
| Gaskets | Buna N |
| Socket | Brass |
| Bourdon Tube | Phosphor bronze C tube to 600 psi (this range: Phosphor bronze C tube) |
| Connecting Joints | Silver brazed |
| Movement | Bushed stainless steel rotary |
| Pointer | Black aluminum, micrometer adjustable |
| Accuracy | 0.5% ASME B40.1 Grade 2A |
| Connection | 1/4″ NPT lower |
| Temperature Limits | Glycerin fill: ambient 20°F to 150°F, process 20°F to 150°F, storage 0°F to 150°F. Silicone fill: ambient -40°F to 150°F, process -40°F to 200°F, storage -40°F to 150°F |
Source Notes
Source note: Fill fluid. The LF4UGY submittal publishes temperature limits for both glycerin and silicone fill. The part number does not encode the fill fluid, so both sets of limits are shown; confirm the fill with the factory.
Source note: Window. Three Weiss documents differ. The 2019 LF4UGY1/LF4UGY2 and NF4UGY1/NF4UGY2 series submittal drawings, linked below, specify a tempered glass window with shatter proof glass or acrylic available. An earlier 2018 NF4UGY dry drawing specifies plain glass, and the Specialty Pressure Gauges catalog specifies acrylic. This page publishes the value from the current exact-series submittal.
Source note: Case material naming. The submittal drawing names the case material polybutylene terephthalate (PBT); the Specialty catalog names it Pocan, a PBT trade name. Both describe the same material.
Source note: Part number decode. The range and connection segments of this part number are decoded with the Weiss code convention published in the Weiss Stainless Steel Case Gauges catalog To Specify table (numeric code = 0 to that psi, VAC = 0-30 inHg vacuum, V code = 30 inHg vacuum to that psi, 4L = 1/4 in lower, 4B = 1/4 in back); this family's own documents do not print a code table.
Documentation
LF4UGY1 / LF4UGY2 Submittal Drawing- Weiss Specialty Pressure Gauges Catalog
- UGY Process Gauge Instructions
Related Products
Frequently Asked Questions
What range does the LF4UGY1-V30-4L read?
30″Hg-0-30 psi.
What is the process connection?
1/4″ NPT lower.
How accurate is it?
The published accuracy for this series is 0.5% ASME B40.1 Grade 2A.
What are the wetted materials?
Socket: Brass; Bourdon Tube: Phosphor bronze C tube to 600 psi (this range: Phosphor bronze C tube).
Manufacturer Warranty
Miljoco-Weiss warrants this product to be free from material defects in material and workmanship for 12 months from date of shipment, per the published Miljoco-Weiss terms and conditions of sale.
Warranty service requires written notice of the defect within seven days of discovery. Remedy is repair, replacement or credit at the manufacturer's discretion. Normal wear, corrosion, misuse and unauthorized modification are excluded.
- Type:
- Pressure Gauge
- Series:
- LF4UGY1
- Dial Size:
- 4-1/2 in
- Pressure Range:
- 30 inHg-0-30 psi
- Range Type:
- Compound
- Connection Size:
- 1/4 in
- Connection Location:
- Lower
- Case Material:
- Reinforced PBT
- Wetted Material:
- Phosphor Bronze
- Fill:
- Liquid Filled
- Accuracy:
- Plus or Minus 0.5 Percent
