Diaphragm Seal and select it

Seal diaphragms are used in processes in which a pressure sensor or level gauge requires separation from the process fluid. These fluids may have corrosion, high temperature, the possibility of crystallization, or the release of a sanitary liquid into the tube or tank.
Instead of connecting the process, pressure is applied to the flexible diaphragm and transmitted through a non-Newtonian fluid to the pressure gauge. When the seal diaphragm is properly installed and filled, it can have the least impact on the performance of the pressure gauge.
Flood diaphragms need to be carefully designed, fabricated, and tested to maximize performance and extend the life of instrumentation equipment.

The following should be considered when buying a flood diaphragm:

1-Is there enough displacement to transfer pressure? 

2-Is the aperture sensitive enough for the measuring range and accuracy of the device?

3-What is the pressure and temperature limit of the fluid?

4-Is there a high viscosity clog?

5-Is there shock and severe fluid beats?

6-Is the device connected directly to the seal diaphragm or is it installed with a capillary?

7-Is the external environment corrosive?

Types of Diaphragm:

1-Miniature model:

Miniature diaphragms are used to measure the pressure of fluids in which there is a high temperature, high viscosity (fluid in the form of a paste) or a tendency for the fluid to crystallize.

Aggressive or crystalline fluids or solids containing solids cannot penetrate the measurement system.

A miniature aperture transmits process pressure by measurement. Due to their compact dimensions, these apertures are widely used to solve measurement problems in confined spaces. These devices can be used for Bourdon gauges with small screens.

The diaphragms mounted on the front of the flood diaphragm are made of 1.4571 stainless steel.

Measurable pressure range for this equipment is 0 Bar 10 Barg and 0 ~ 100 Barg.

Capillary tube with a length of 15 meters can be installed on this equipment, but if the fluid has a high temperature, due to the temperature difference in the capillary tube, the pressure measured by the measuring equipment will have an error.

For places where the fluid has a temperature above 100 degrees, it is recommended to use the cooling element instead of capillary.

2- Threaded _ screw  model
Thread-screw diaphragms are one of the most common and widely used types of diaphragms that cover a high compression range. There is no fluidity.

Aggressive or crystalline fluids or solids containing solids cannot be used in this diaphragm model due to the small opening.

The lower part of this type of diaphragm can be replaced according to the type of fluid.

Due to their dimensions, these diaphragms are not used to solve measurement problems in confined spaces, This equipment can be used for Bourdon gauges with any screen size.

The diaphragm mounted on the front of the flood diaphragm is made of 1.4571 stainless steel.This material can be changed according to the order of the employer.

Measurable pressure range for this equipment is -1.1 Barg and 0 ~ 20 Barg.

Capillary pipe with a length of 15 meters can be installed on this equipment But if the fluid has a high temperature Due to the temperature difference in the capillary tube, the pressure measured by the measuring equipment has an error.

For places where the fluid has a temperature above 100 degrees, it is recommended to use the cooling element instead of capillary.

3-Diaphragm seal with threaded connection

Diaphragms seal with threaded connection are less commonly used due to their high cost, but can transmit very different compression ranges with high accuracy.
It is used to measure the pressure of liquids in which there is no medium temperature, medium and low viscosity and no tendency to crystallize in the fluid.

Aggressive or crystalline fluids or solids containing solids cannot be used in this diaphragm model due to the small opening.
This equipment can be used for Bourdon gauges with any screen size.
The diaphragm mounted on the front of the flood diaphragm is made of 1.4571 stainless steel, this material can be changed according to the client's order.
Measurable pressure range for this equipment is -1.1 Barg and 0 ~ 200 Barg.
Capillary tube with a length of 15 meters can be installed on this equipment, but if the fluid has a high temperature, due to the temperature difference in the capillary tube, the pressure measured by the measuring equipment will have an error.
For places where the fluid has a temperature above 100 degrees, it is recommended to use the cooling element instead of capillary.

4- Flange diaphragm

Flange diaphragms are very common due to the ability to connect the flange and the fact that the fluid is not blocked inside a chamber and can transmit a very different compression range with high accuracy.
Used to measure the pressure of fluids in which the temperature has a wide range, the viscosity of the fluid does not matter and there is a tendency for it to crystallize in the fluid.
Aggressive or crystalline fluids or solids containing solids can be used in this model of diaphragms due to their large opening and direct connection. Such diaphragms should be used for fluids that contain abrasive solids in such a way that the diaphragm is not subject to permanent erosion or the diaphragm material is considered to be resistant to erosion.
This equipment can be used for Bourdon gauges with any screen size.
The diaphragm mounted on the front of the flood diaphragm is made of 1.4571 stainless steel, this material can be changed according to the client's order.
Measurable pressure range for this equipment is -1.1 Barg and 0 ~ 600 Barg.
Capillary tube with a length of 15 meters can be installed on this equipment, but if the fluid has a high temperature, due to the temperature difference in the capillary tube, the pressure measured by the measuring equipment will have an error.
For places where the fluid has a temperature above 100 degrees, it is recommended to use the cooling element instead of capillary.

5-Clamp Diaphragm

Food diaphragms are used only in the food industry and can transmit very different pressure ranges with high accuracy. They can also be opened and closed quickly.
It is used to measure the pressure of fluids in which there is no medium temperature, medium and low viscosity and no tendency to crystallize in the fluid.
Aggressive or crystalline fluids or solids containing solids can be used in this diaphragm model.
This equipment can be used for Bourdon gauges with any small screen size (less than 10 cm).
The diaphragm mounted on the front of the flood diaphragm is made of 1.4571 stainless steel, this material can be changed according to the client's order.
Measurable pressure range for this equipment is -1.1 Barg and 0 ~ 200 Barg.
Capillary tube with a length of 15 meters can be installed on this equipment, but if the fluid has a high temperature, due to the temperature difference in the capillary tube, the pressure measured by the measuring equipment will have an error.
For places where the fluid has a temperature above 100 degrees, it is recommended to use Cooling Element instead of capillary.
Author: Parto Sahand Ara Company
Date: 12/05/1400