Product Description

Product Name:  
Rigid coupling for connecting fire protection pipe

Material:
Ductile cast iron 

Standard: 
UL listed & FM approved
also wen can manufacture different sizes according to client’s requirements.

Sizes available: 

Nominal size		Pipe O.D.		Working pressure		Dimensions						Bolt size
						∅		L		H
mm	in	mm	in	PSI	Mpa	mm	in	mm	in	mm	in	mm
25	1	33.7	1.327	300	2.07	55.6	2.188	98	3.858	44	1.732	M10*45
32	1 1/4	42.4	1.699	300	2.07	66	2.598	107	4.213	44	1.732	M10*45
40	1 1/2	48.3	1.9	300	2.07	74	2.913	115	4.527	44	1.732	M10*45
50	2	60.3	2.372	300	2.07	84	3.307	124	4.882	44	1.732	M10*55
65	2 1/2	73	2.875	300	2.07	98	3.858	138	5.433	45	1.772	M10*55
65	2 1/2	76.1	3	300	2.07	100	3.937	143	5.63	45	1.772	M10*55
80	3	88.9	3.5	300	2.07	114	4.488	157	6.181	45	1.772	M10*55
100	4	114.3	4.5	300	2.07	140	5.512	187	7.362	50	1.899	M10*65
125	5	139.7	5.5	300	2.07	172	6.771	220	8.661	50	1.899	M12*70
125	5	141.3	5.563	300	2.07	172	6.771	220	8.661	50	1.899	M12*75
150	6	165.1	6.5	300	2.07	197	7.756	252	9.921	51	2.008	M12*75
150	6	168.3	6.625	300	2.07	197	7.756	255	10.039	51	2.008	M12*75
200	8	219.1	8.625	300	2.07	254	10	330	12.992	61	2.405	M16*100
250	10	273	10.75	300	2.07	317	12.48	397.8	15.661	62	2.441	M20*110
300	12	323.9	12.751	300	2.07	370	14.566	457	17.992	60	2.362	M20*120

We can manufacture different sizes according to your requirements.

How Does a Rigid Coupling Protect Connected Equipment from Shock Loads and Vibrations?

Rigid couplings play a crucial role in protecting connected equipment from shock loads and vibrations by providing a direct and rigid connection between the shafts. The design and properties of rigid couplings contribute to their ability to mitigate the impact of shock loads and vibrations in the following ways:

– High Stiffness: Rigid couplings are constructed from materials with high stiffness, such as steel or aluminum. This high stiffness allows them to resist deformation and bending under load, ensuring that the coupling remains stable and maintains its shape. As a result, the shock loads and vibrations are not amplified or transferred to the connected equipment.

– Immediate Torque Transmission: Rigid couplings provide immediate torque transmission between the shafts without any backlash or play. When the connected machinery experiences a sudden shock load, the rigid coupling effectively transfers the torque to the other side of the coupling without delay. This rapid and precise torque transfer prevents the shock load from causing misalignment or damaging the equipment.

– Elimination of Damping: Unlike flexible couplings, which can dampen vibrations to some extent, rigid couplings do not have any damping properties. While damping can be beneficial in certain applications, it can also allow vibrations to persist, potentially affecting the performance and reliability of the connected equipment. Rigid couplings do not introduce any additional damping, ensuring that the vibrations are not prolonged.

– Stable Connection: Rigid couplings create a stable and unyielding connection between the shafts, limiting any relative movement. This stability prevents the propagation of vibrations from one shaft to another, reducing the potential for resonance and vibration amplification.

– Minimal Maintenance: Rigid couplings require minimal maintenance due to their simple and durable design. Unlike flexible couplings that may have wear-prone elements, rigid couplings do not have parts that need regular replacement. This reliability and low maintenance contribute to their ability to provide continuous protection against shock loads and vibrations.

In applications where shock loads and vibrations are prevalent, using a rigid coupling can help protect critical machinery and components from damage and premature failure. By providing a rigid and immediate torque transmission, rigid couplings effectively isolate the connected equipment from the harmful effects of shock loads and vibrations, ensuring smooth operation and enhanced reliability.

How Does a Rigid Coupling Handle Angular, Parallel, and Axial Misalignment?

Rigid couplings are designed to provide a fixed and rigid connection between two shafts. As such, they do not have any built-in flexibility to accommodate misalignment. Therefore, when using a rigid coupling, it is essential to ensure proper shaft alignment to avoid excessive forces and premature wear on connected equipment.

Angular Misalignment: Angular misalignment occurs when the axes of the two shafts are not collinear and form an angle with each other. Rigid couplings cannot compensate for angular misalignment, and any angular misalignment should be minimized during installation. Precision alignment techniques, such as laser alignment tools, are often used to achieve accurate angular alignment.

Parallel Misalignment: Parallel misalignment, also known as offset misalignment, happens when the axes of the two shafts are parallel but have a lateral displacement from each other. Rigid couplings cannot accommodate parallel misalignment. Therefore, precise alignment is crucial to prevent binding and excessive forces on the shafts and bearings.

Axial Misalignment: Axial misalignment occurs when the two shafts have an axial (longitudinal) displacement from each other. Rigid couplings cannot address axial misalignment. To prevent thrust loads and additional stresses on bearings, it is essential to align the shafts axially during installation.

In summary, rigid couplings are unforgiving to misalignment and require precise alignment during installation. Any misalignment in a rigid coupling can lead to increased wear, premature failure of components, and reduced overall system efficiency. Therefore, it is crucial to use appropriate alignment techniques and tools to ensure optimal performance and longevity of the connected equipment.

Limitations and Disadvantages of Using Rigid Couplings:

Rigid couplings offer several advantages in providing a strong and direct connection between shafts, but they also have certain limitations and disadvantages that should be considered in certain applications:

• No Misalignment Compensation: Rigid couplings are designed to provide a fixed connection with no allowance for misalignment between shafts. As a result, any misalignment, even if slight, can lead to increased stress on connected components and cause premature wear or failure.
• Transmit Shock and Vibration: Rigid couplings do not have any damping or vibration-absorbing properties, which means they can transmit shock and vibration directly from one shaft to another. In high-speed or heavy-duty applications, this can lead to increased wear on bearings and other components.
• No Torque Compensation: Unlike flexible couplings, rigid couplings cannot compensate for torque fluctuations or angular displacement between shafts. This lack of flexibility may not be suitable for systems with varying loads or torque requirements.
• Higher Stress Concentration: Rigid couplings can create higher stress concentration at the points of connection due to their inflexibility. This can be a concern in applications with high torque or when using materials with lower fatigue strength.
• More Challenging Installation: Rigid couplings require precise alignment during installation, which can be more challenging and time-consuming compared to flexible couplings that can tolerate some misalignment.
• Increased Wear: The absence of misalignment compensation and vibration absorption can lead to increased wear on connected components, such as bearings, shafts, and seals.
• Not Suitable for High Misalignment: While some rigid couplings have limited ability to accommodate minor misalignment, they are not suitable for applications with significant misalignment, which could lead to premature failure.

Despite these limitations, rigid couplings are still widely used in many applications where precise alignment and a strong, permanent connection are required. However, in systems with significant misalignment, vibration, or shock loads, flexible couplings may be a more suitable choice to protect the connected components and improve overall system performance and longevity.

editor by CX 2023-08-18