Hard seal and soft seal can complement each other, as for the sealing soft seal is relatively good, but now hard seal sealing can also meet the corresponding requirements, the advantage of soft seal is sealed performance is good, defect is easy ageing, wear and short service life.Hard seal service life is long, but the sealing is relatively worse than soft seal.

Soft seal: seal on both sides of a side is the metal material, on the other side is elastic non-metallic materials are referred to as "soft seal". This kind of seal sealing performance is good, but not high temperature resistant, easy to wear and poor machinery.Such as: steel + rubber;Steel + four fluorine polyethylene, etc.

Soft seal refers to seal the side is to use low hardness material, in general, soft seal USES a certain strength, hardness and heat resistance properties of non-metallic materials, sealed performance is good, can achieve zero leakage, but life and adaptability to temperature with poor hard seal made of metal sealing performance is relatively poor, despite the manufacturers claim to achieve zero leakage.Soft seal part of corrosive material can't meet the technological requirements, hard seal can solve!

Hard seal, seal on both sides of all is the metal material or other hard materials are called "hard seal". This kind of seal sealing performance is poor, but high temperature resistance, wear resistance, good mechanical performance.

Soft seal and hard seal each have advantages and disadvantages:

Soft sealing advantages: sealing performance can be to level 6, and the seat of the maintenance easy to change.The valve torque is small, can save the cost of the actuator.Manufacturing cost is low, processing cheap, short delivery cycle.Commonly used in relatively clean, low viscosity liquid and gas.The disadvantage is that: high temperature resistant, not wear-resisting.+ Z!X, \, S4 c % r

Hard seal advantages: the valve core seat can do a lot of kinds of combinations, the surface spray technology applied to the valve on the abrasion resistance to high temperature corrosion condition has very good application, long service life.Weakness: the manufacturing cost is high, the valve core seat maintenance replacement usually require overall grinding, site maintenance is not convenient.A fairly large valve torque.

1, in terms of sealing material

Elastic soft-sealing gate valve and hard seal gate valves are for the seat of the sealing material.Hard seal is to use the seat material precision machining, generally speaking, there are stainless steel and copper.Soft seal is set in the seat sealing material for non-metallic materials, because of the soft sealing materials have certain elasticity.So hard seal will be relatively low demands on machining accuracy.

2, manufacture process

Hard seal gate valves are generally required to do hardening treatment, between the ball and seat to grinding to seal production cycle is long, processing is more complex, hard seal ball valve is not easy to do.

3, terms of use

Elastic soft-sealing gate valve seal can achieve high commonly, while hard seal according to the requirements can be high to low;Hard seal generally can do high pressure, soft seal is not;Soft seal due to the problem of flow medium, is can't use some occasions.