YTP Diaphragm Pressure Gauge

Diaphragm pressure gauges are suitable for measuring the pressure of highly corrosive, high-temperature, high-viscosity, easily crystallized, easily solidified media with suspended solids, as well as applications where it is necessary to prevent the measured medium from directly entering general-purpose pressure instruments and to avoid sediment accumulation while being easy to clean.

Product Introduction

The diaphragm pressure gauge consists of a diaphragm isolator and a general-purpose pressure instrument forming a system.

The connection methods of diaphragm pressure gauges to equipment mainly include threaded connections, flange connections, and sanitary clamp types.

Diaphragm gauges are primarily used in industrial sectors such as petrochemicals, alkali production, chemical fibers, dyeing, pharmaceuticals, food, and alkali manufacturing for measuring fluid medium pressure during production processes.

Diaphragm Pressure Gauge Structural Principle

When the pressure P of the measured medium acts on the diaphragm, the diaphragm deforms, compressing the sealing fluid in the pressure measurement system of the pressure instrument, forming a pressure of P-△P. When the rigidity of the diaphragm is sufficiently small, △P is also very small, and the pressure formed by the pressure measurement system of the pressure instrument approximates the pressure of the measured medium.

Technical Specifications

1. Temperature Characteristics:

Since the diaphragm pressure gauge system uses filled sealing fluid as the medium for transmitting pressure, the temperature expansion coefficient of the sealing fluid causes the instrument's indication value to increase as the temperature of the pressure-bearing part rises. The temperature influence depends on the expansion coefficient of the sealing fluid, the stiffness of the diaphragm, and the temperature of the pressure-bearing part. This effect is particularly significant for low-range pressure instruments. Generally, the temperature error of the pressure-bearing part is specified to be no greater than 0.1%/℃. Therefore, the overall temperature influence of the diaphragm pressure gauge is typically the sum of the temperature influence of the general-purpose instrument and the temperature influence of the pressure-bearing part of the diaphragm device.

2. Accuracy Class: 1.6; 2.5

3. Measurement Range (MPa): Threaded Connection Type: ~0.1~0/0~60/0~100

Flange Connection Type: ~0.1~0/0~25

Sanitary Clamp Type: ~0.1~0/0~2.5

4. Diaphragm Materials: 0Cr17Ni12Mo2 (316); Monel Alloy (Cu30Ni70); Hastelloy (H276C); Tantalum (Ta); and Fluoroplastic (F4).

5. Internal Filling Working Fluid: (1) Silicone Oil; (2) Custom-filled according to customer requirements

6. Operating Conditions:

(1) Temperature: Ambient temperature -20~+55℃; Measured medium temperature -20~+55℃

(2) Working Pressure: Static load: Up to 3/4 of the upper measurement limit

(3) Alternating load: Up to 2/3 of the upper measurement limit

(4) Short-term pressure: Up to the upper measurement limit

7. Connection Dimensions

(1) Threaded Connection: M20*1.5 (G3/8″ G1/2″)

(2) Flange Connection:

A. Ministry of Machinery Industry Standard JB81-94 "Flat Welded Steel Flange"

B. Ministry of Chemical Industry Standard "Acid-Resistant Flat Welded Steel Flange"

C. Customized according to user requirements

8. Instrument Diameter: φ60mm; φ75mm; φ100mm; φ150mm

9. Instrument Execution Standard: JB/T8624-1997

Liquid Level Difference Explanation

Especially for diaphragm pressure gauges with flexible connecting pipes, due to the different installation positions of the pressure-bearing part and the general-purpose pressure gauge, a liquid level difference influence amount △P will occur as shown in the figure.

Corrosion Resistance Explanation

The corrosion resistance of the diaphragm pressure gauge can be ensured by selecting appropriate materials for the isolation diaphragm, flange, and sealing gasket that come into contact with the measured medium.

Diaphragm Materials: 0Cr17Ni12Mo2 (316); Monel Alloy (Cu30Ni70); Hastelloy (H276C); Tantalum (Ta); and Fluoroplastic (F4).

Flange Materials: Stainless Steel 0Cr17Ni12Mo2 (316); Stainless Steel Lined with Fluoroplastic (316+F4).

Sealing Gasket Materials: Nitrile Rubber; Fluororubber; Silicone Rubber; and Fluoroplastic.

Model Marking Example Introduction

Marking 1; Y-100B/SR/MF（A）316/4MPa/50-4.0HGJ46

General instrument is Y-100B stainless steel pressure gauge, connection type is SR heat dissipation type, using open convex flange MF isolator (flange) material is carbon steel, diaphragm material is 316 stainless steel, measurement range 0～4MPa, flange standard 50-4.0HGJ46

Marking 2; YSG-2/ZMG（B）Hastelloy/1MPa/20-4.0Hgj47

General instrument is YSG-2 inductive pressure transmitter, connection form is direct. Using I-shaped flange MG, isolator (flange) material is 1Cr18Ni9, diaphragm material is Hastelloy alloy, measurement range 0～1MPa, flange standard is 20-4.0HGJ47.

Marking 3; Y-100B/SR/ML 316/4MPa/M20*1.5

General instrument is Y-100B stainless steel pressure gauge, connection type is SR heat dissipation type, using threaded connection ML isolator material is stainless steel, diaphragm material is 316 stainless steel, measurement range 0～4MPa, thread specification M20*1.5

Ordering Instructions

1. When ordering, please specify the model, name, measurement range, measured medium, working temperature, connection form and dimensions, and accuracy class.

2. If there are special requirements, please provide detailed instructions when ordering.

3. Do not disassemble or replace the configured instrument of the diaphragm pressure gauge to avoid leakage of the filling fluid affecting performance.

4. Before ordering, based on the characteristics of the measured medium, such as corrosiveness, tendency to solidify, or crystallize, select a stainless steel pressure gauge for corrosive media according to their properties or use diaphragm pressure gauges with different corrosion-resistant diaphragm materials. For high-temperature environments, use high-temperature melt diaphragm pressure gauges. For general media (such as water, gases non-corrosive to copper or copper alloys), general pressure gauges can be used.